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Hong Kong Diploma of Secondary Education ExaminationIntegrated ScienceSchool-based Assessment Sample TasksNon-Practical Related TasksTeachers may use the sample tasks for non-profit making educational and research purposeswith proper �� 2010Hong Kong Examinations and Assessment AuthorityAll Rights Reserved 2010
TABLE OF CONTENTTaskTitleC3Shock Absorbance Effectiveness of Air-cushioned Sports ShoesC6Oil Spill and Related Environmental ProblemsC7Do Mobile Phones Pose Health Risks?E1Fireworks and Air PollutionE2Influenza and Our Health
Integrated ScienceSample SBA TaskNon-Practical Related Task – C3Shock Absorbance Effectiveness of Air-cushioned Sports ShoesStudents’ HandoutMany sports shoe manufacturers produce running shoes that feature air cushions. It isclaimed that the air cushions absorb the shock experienced by the runner by reducing theimpact force and hence minimising the chance of injuries to the legs and feet.You are going to investigate the shock absorbance effectiveness of air-cushioned sports shoesand prepare to submit an investigation proposal to a science project competition.The teacher advisor suggests you work through some background information (Source A)and study an experiment performed previously by other students (Source B) before writingthe proposal (the task). Each of the sources is accompanied with several questions to helpyou better understand the investigation and to formulate the investigation proposal.Source A: Some physics of impact force in runningQ1. Fig. 1 shows a standing person, John. Draw on Fig. 1 the action and reaction forcesbetween John and the ground. Name the forces.(2 marks)Fig. 1Student Handout–C3(NP)page 1 of 7
Integrated ScienceSample SBA TaskQ2. Fig. 2 shows another person, Peter, who is running.John.(a)(b)(c)Peter has the same weight asDraw on Fig. 2 the action and reaction forces between Peter and the ground.Suggest why the action and reaction forces acting in Peter’s case are larger thanthose in John’s case.Identify the “impact force” that needs to be studied in the investigation.(4 marks)Fig. 2Air-cushioned sports shoes have air-filled chambers in the soles.that the air cushions help reduce the impact force while running.Shoe manufacturers claimQ3. Given the same impulse, explain how these air cushions help reduce the impact force.(3 marks)Source B: Experimental measurement of impact forceSome students have previously performed the following experiment to measure impact force.Instead of running on a track, they designed a laboratory set-up to simulate the impact.Design of the experimentOne student, Mary, wearing a pair of sports shoes, jumped from a stool onto a force platformplaced on the ground (see Fig. 3). The force platform was connected to a data-loggingsystem. Fig. 3Student Handout–C3(NP)Design of the experimentpage 2 of 7
Integrated ScienceSample SBA TaskQ4. Suggest ONE reason why it is difficult to collect data from a running person.(1 mark)Q5. State TWO factors that need to be considered in setting the height of the stool in thesimulation.(2 marks)Q6. Mary was told to fix her posture and minimise movements of her other body partsduring the jump. Why is this important ?(2 marks)Data analysisFig. 4 shows the impact force-time graph obtained when Mary wore a pair of sports shoeswithout air cushions.350030002500N/ 2000ercoftcap1500mI1000500000.511.522.53Time / sFig. 4 Impact force-time graphQ7. Given that the weight of a body is the Earth’s gravitational force acting on it, estimatefrom the graph the weight of Mary.(1 mark)Q8. (a)(b)With reference to Fig. 4, what is the ratio of the maximum impact force to thebody weight (BW) of Mary?Data collected from people running in bare feet show that the maximum impactforce is about 3 times of BW. Suggest and explain how the validity of theexperiment can be improved.(3 marks)Student Handout–C3(NP)page 3 of 7
Integrated ScienceSample SBA TaskQ9. Suppose that Mary wears a pair of sports shoes with air cushions and repeats theexperiment. Sketch on Fig. 4 the impact force-time graph that would be obtained.(You may assume that Mary again hits the force platform at the same moment as thejump in Fig.4.)(2 marks)THE TASKYou are going to devise an investigation after studying the above information.necessary to formulate firstly the purpose of the investigation.It isQ10. In a simple sentence, write down the purpose of the investigation.(2 marks)Next, you need to write up a proposal of the investigation. The proposal will be submittedto the judge panel of the science project competition to help them judge the worth of the ideasunderlying the investigation. The proposal should address the points listed below: Why is shock absorbance important in sports shoes ?What is the purpose of the investigation ?What is your experimental set-up ?How are data collected and analysed ?What is/are the importance/application(s) of your findings ?Q11. Write up the proposal for submission.Student Handout–C3(NP)The word limit of the proposal is 300.(10 marks)page 4 of 7
Integrated ScienceSample SBA TaskAN EXTENDED TASK: Experimental measurement of the Peak Tibial AccelerationIn running or other exercises, the impact force not only acts on our feet, it transfers up ourskeleton. The tibia is the larger bone in the leg (see Fig. 5). It bears most of the shockwhile running. As such, scientific research on sports mechanics used to focus on aparameter called ”Peak Tibial Acceleration” (PTA).Fig. 5Bones of the lower extremityQ12. How is PTA related to the shock acting on the tibia?(1 mark)Q13. If PTA becomes too large, what might happen to the tibia?(1 mark)You are required to study the following experiment on the measurement of PTA and answerthe questions that follow.Design of the experimentA 3D-accelerometer is tied to the leg of a student with an elastic bandage, as shown in Fig. 6.The accelerometer measures the acceleration of the object it is attached to. Data are beingcollected during the jump as in the experiment in Source B.Fig. 6Student Handout–C3(NP)Attachment of a 3D-accelerometer to the legpage 5 of 7
Integrated ScienceSample SBA TaskQ14. If the accelerometer is not tied tightly to the leg, how would it affect the measurement ?(2 marks)Data analysisFig.7 and Fig.8 respectively show the tibial acceleration-time graph obtained in a trial jumpand the corresponding impact force-time 500.51.5122.532.53Time / sFig.7 Tibial acceleration-time graph30002500N/ 2000ercoftcap1500mI1000500000.511.52Time / sFig. 8 Impact force-time graphStudent Handout–C3(NP)page 6 of 7
Integrated ScienceSample SBA TaskQ15. From the graphs, identify the following stages in the jump:(a)(b)(c)(d)exerting of force in jumping up,falling through the air,touching down on the force platform, andfinally standing still.(2 marks)Q16. What is the PTA as determined in this experiment?(1 mark)ENDStudent Handout–C3(NP)page 7 of 7
Integrated ScienceSample SBA TaskNon-Practical Related Task – C6Oil Spill and Related Environmental ProblemsStudent HandoutCrude oil is a source of energy and raw material for making plastics and other petrochemicals.Not many places in the world produce oil, and some of them cannot produce enough oil fortheir own use. Thus, oil needs to be transported from the point of production to the point ofuse. This is achieved mainly by pipelines on land or via oil tankers across the oceans.In this exercise, you are required to study information from three different sources (A to C)and answer the questions accompanying each source.Source A:An article on oil spill off the coast of South Korea in December, 2007A Hong Kong-registered oil tanker leaked over 10,000 tonnes of crude oil after it collided with abarge last Friday off the coast of South Korea. The collision caused gashes in the tanker’s hull andthe spilled oil spread over 20 km from the site of the accident due to a combination of wind andsea current, polluting the famous Mallipo beach and the fish farms there. This might be the largestecological disaster ever in South Korea.The black crude oil was washed ashore onto the Mallipo beach in a slick of 10 cm thick.Thousands of troops, police and local residents helped remove the crude oil. Hundreds of farms inthe area producing seafood including abalone, oyster and sea cucumber were affected.Mallipo’s national maritime park and wildlife habitats, whichserve as a stopover for migratory birds, were also affected bythe spill. Seabirds, like the one shown in the photo, werecovered in crude oil. A lot of birds have died. Officials believethat the spill will not spread further; however, it will take overa month to do the clean-up.Q1.State TWO threats of the oil spill to the environment of Mallipo.(2 marks)Q2.A lot of dead seabirds covered with thick oil were found in the affected area. SuggestTWO ways that oil spills affect these animals and cause death.(4 marks)Q3.Explain whether humans are affected by marine oil spills.(2 marks)Student Handout – C6(NP)page 1 of 3
Integrated ScienceSample SBA TaskQ4. Many marine oil disasters are due to oil spills caused by the holing of oil tankers’ hulls.Suggest a design for oil tankers that could help reduce oil spill.(1 mark)Source B:Clean-up of the Exxon Valdez oil spillOn March 24, 1989, the tanker Exxon Valdez, en route from Alaska to California, ran aground onBligh Reef in Prince William Sound, Alaska. Within six hours of the grounding, the tanker spilledapproximately 10.9 million gallons of crude oil. Several measures were taken to clean up the spill.Before the oil spread to shoreline, long buoyant booms, which float on water, were deployedaround the vessel to keep the oil from spreading (Fig. 1). The oil was then recovered byskimmers.Fig. 1 The Exxon Valdez surrounded by acontainment boom (Photo courtesy of the ExxonValdez Oil Spill Trustee Council)Fig. 2 Beach washing (Photo courtesy of theExxon Valdez Oil Spill Trustee Council)For the beach clean-up, hoses spraying seawater were used to flush oil from shorelines (Fig. 2).The released oil was then trapped with an offshore boom, and removed using skimmers andvacuum trucks. Along with large-scale beach washing, manual clean-up of oily debris was used.In some locations, oil was thick enough to be picked up with shovels and buckets.Beach applications of dispersants were tried in several locations. No significant change in oilcover was observed as a result of the treatment. Some ecological impacts were observed in thetreated areas. By the end of the clean-up in 1989, more than 25,000 tonnes of oiled waste andseveral hundred thousand barrels of oil/liquid waste had been collected and disposed of inlandfills.(Source: http://www.eoearth.org/article/Exxon Valdez oil spill)Q5.Give TWO ways that can be employed to contain or to remove spilled oil.(2 marks)Q6.Suggest TWO factors that affect the spread of oil on sea surface.(2 marks)Student Handout – C6(NP)page 2 of 3
Integrated ScienceSample SBA TaskQ7.Suggest ONE condition under which booms will not be effective in trapping released.(1 mark)Q8.Dispersants may be used to remove spilled oil but they can cause other environmentalproblems. Suggest and explain ONE environmental problem caused by the use ofdispersants.(2 marks)Source C:An article on the closing of a bathing beach in August, 2009Yesterday at around 10 am, staff of the Leisure and Cultural Services Department found an oilspill covering an area of 40 m 50 m on Lo Sho Shing Beach, Lamma Island. The source forthe oil spill could not be identified. The Department announced a temporary closing of the beachuntil further notice.The government will arrange for a clean-up of the oil spill by using sorbents and then carry out ananalysis of water samples before deciding on when to re-open the beach.The Beach Water Quality Report issued by the Environmental Protection Department in 2008showed that out of the 41 beaches in Hong Kong, Lo Sho Shing Beach was regarded the third bestbeach after Hung Shing Yeh Beach and Hap Mun Bay, Sai Kung. Its water quality was rankedGrade 1 (Good); however, the beach is occasionally affected by oil spill from unknown sources.(Source: Ming Pao News, August 17, 2009)Q9.Suggest TWO possible reasons for the oil spill that occurred in Lo Sho Shing Beach.(2 marks)Q10. Suggest why using sorbents to clean up the oil spill in Lo Sho Shing Beach iseffective.(2 marks)Q11. Suggest a major parameter used in determining beach water quality.(1 mark)Q12. Other than the parameter suggested in Q11, give TWO other parameters commonlyused in determining beach water quality.(2 marks)ENDStudent Handout – C6(NP)page 3 of 3
Integrated ScienceSample SBA TaskNon-Practical Related Task – C7Do Mobile Phones Pose Health Risks?Student HandoutThe controversial issue of whether mobile phones pose health risks has recently becomeheadline news. There are concerns about the risk of brain cancer caused by the head’sabsorption of electromagnetic radiation while using mobile phones. A lot of research hasbeen done on investigating possible health risks caused by using mobile phones. Somescientists claim that the increasing number of brain tumours is linked to heavy mobile phoneusage. Some other scientists, however, refute the claim on the basis that there is noconclusive evidence. As a layman, how would you judge the issue after reading these newsreports?Study Sources A to E below and answer the questions acompanying the tasks.Source A: Number of digital mobile phone subscribers in Hong Kong from 1993 to 511993-1994Number of mobile phone subscribers(million)Digital mobile phone subscribers in Hong /hktelecom-indicators summary.html)Source B: Research on the relationship between the use of mobile phones and health risksA university research student conducted an information search on the Internet with aparticular combination of related keywords about the number of research studies on therelationship between the use of mobile phones and health risks. He made the followingtallies:Student Handout – C7(NP)page 1 of 4
Non-Practical Related TaskYear1990-19941995-19992000-20042005-2008Q1.No. of researchpapers publishedby independentuniversityresearchers53175389545No. of researchpapers publishedand sponsored bymobile phonemanufacturers142988351613Total no. ofresearch paperspublishedAverage no. ofresearch paperspublished per year674731224215813.494.6244.8539.5With reference to Source A and Source B, suggest a reason why very few researchpapers on the relationship between the use of mobile phones and health risks wascarried out before 1995.(1 mark)Q2. Much of such research was conducted or sponsored by manufacturers of mobile phones.Suggest a reason for this.(1 mark)Q3. Explain why it may take many years to get definite results on whether heavy usage ofmobile phones may have health effects on users.(2 marks)Source C: An excerpt adapted from a newspaper:Brain Cancer Cases Double in 11 YearsIn tandem with the increasingly widespread use of mobile phones, the number ofreported cases of brain cancer have almost doubled in 11 years. This raisesconcerns about mobile phones being a possible cause of brain cancer.According to official figures, there were only 517 cases of brain cancer diagnosedin 1991, but the number of cases rose to 1532 in 2002, showing a sharp increase of196% in a little over ten years. When buying mobile phones, health cautious consumers should make reference tothe Specific Absorption Rate (SAR), which is a scale for measuring the rate at whichelectromagnetic radiation energy is actually absorbed by human tissue, in watts perkilogram units (W/kg). The larger the SAR value, the more radiation will beabsorbed by human tissue.The accepted limit of SAR in Europe is 2.0 W/kg, while that in America andAustralia is 1.6 W/kg.Student Handout – C7(NP)page 2 of 4
Integrated ScienceSample SBA TaskQ4.After reading the bar chart of Source A and the newspaper article of Source C, astudent made the following comment:“There is sufficient evidence to support the claim that brain cancer iscaused by the use of mobile phones. This is because during the sameperiod, both the numbers of brain cancer cases and mobile phone usersincreased sharply.”Explain whether you agree with the student.(2 marks)Q5. Apply what you have learnt in Module C7 “Radiation and Us”, and explain briefly whyabsorption of electromagnetic radiation is considered a potential health hazard.(2 marks)Source D: Results from a research study on the absorption of electromagnetic radiation bytissues near human skull of people using mobile phonesAge5101520Q6.Thickness of skull (mm)0.51.01.52.0SAR (W/kg)4.62.41.81.6Write asimple statement to summarise the research result in Source D.(1 mark)Q7.Plot a graph of SAR against age on the grid below.5SAR (W/kg)4321005101520Age(2 marks)Student Handout – C7(NP)page 3 of 4
Non-Practical Related TaskQ8. From your graph, estimate the rate of energy absorption of a child of age 8 with a bodyweight of 30 kg who uses a mobile phone?(2 marks)Q9. If the acceptable SAR limit is 2.0 W/kg, what would you suggest to be the minimumage for a child to use mobile phones?(1 mark)Q10. To address anxiety of consumers about the health risks of using mobile phones,legislators have proposed to enforce the affixing of a label of the SAR value on mobilephones by the manufacturers.Suggest whether you support this legislation and why, as:(a) a mobile phone manufacturer,(b) an officer of the Office of Telecommunications Authority (OFTA), and(c) a consumer.(6 marks)Source E: Articles on the relationship between the use of mobile phones and health risksBelow is background information from five articles about the use of mobile phones andhealth risks.Article 1The newspaper article of Source CArticle 2A research paper, Scientists are divided on health risks caused by using mobilephone, sponsored by a mobile phone manufacturer and published in the journal,Newsletter of Mobile Phone ManufacturersArticle 3A newspaper article quoting results from a research paper, Mobile phone uselinked to tumour, published in the scientific journal, European Journal of RadioFrequencyArticle 4A research paper, Mobiles don’t raise cancer risk, published in the journal,International Journal of Cancer Research, by independent academicsArticle 5A consultant report, It’s safe to use mobile phones, commissioned by thegovernment published by the Faculty of Electrical Engineering of a universityQ11. Arrange the above articles in descending order of reliability. (If necessary, you may use“ ” to indicate articles that are of the same reliability.)(2 marks)Q12. For each article, explain how you would judge its reliability.(5 marks)ENDStudent Handout – C7(NP)page 4 of 4
Integrated ScienceSample SBA TaskNon-Practical Related Task – E1Fireworks and Air PollutionStudent HandoutEvery year since 1997, firework events have been performedregularly in Victoria Harbour on the second day of ChineseNew Year (in January or February) and the National Day(1 October). The issue of air pollution caused by fireworksattracts media attention when environmental groups point outthat the firework display at Hong Kong Disneyland everynight since its opening in 2005 worsen the quality of air.The smoke released from fireworks consists of chemicals thatmight cause air pollution. There is scientific researchshowing that firework displays cause air pollution for a shortperiod of time. It has also been found that weather plays animportant role in causing dispersal or accumulation of thesechemicals in the air. If the weather conditions are favourablefor transporting chemicals away, their effects on air quality will be less significant.TaskEither(I) You are going to role-play a project officer of an environmental group in producing aleaflet to raise people’s concerns about the worsening of air quality caused by fireworks,and hence to convince the public that firework displays should be abolished. You have tosearch for relevant information, analyse the information, and then draw conclusions withsound evidence to support your argument that fireworks worsen air-quality. In the leaflet,you have to provide background information about fireworks and their effects on airquality, and to present the results of your data analysis and the conclusions in a waywhich is easily understood by the public.Note: A leaflet is a single sheet containing printed matter on one or both sides, oftenfolded into two or more leaves but not stitched.Folded toStudent Handout – E1(NP)page 1 of 3
Integrated ScienceSample SBA TaskOr(II) You are going to role-play a government official (e.g. the Secretary for the Environmentor the Secretary for Commerce and Economic Development) in writing a reply to theHong Kong Legislative Council to defend the government’s line in support of fireworkdisplays. When drafting the reply, you have to search for relevant information, analysethe information, and explain that there is no conclusive evidence that fireworks worsenair quality. The reply may include a PowerPoint presentation of the relevant data.The questions raised by a member of the Legislative Council, Mr Wong PM:Hon. WONG PMIt has been reported that firework displays held in Victoria Harbour for festivalcelebrations worsen air quality. Environmental groups have stated that muchscientific research shows that air pollutants released during the fireworkdisplays accumulate to a level of concentration that is harmful to people,especially those living in Central, a district nearby Victoria Harbour.In this connection, will the Government inform this Council:(a) how serious is the air pollution caused by firework displays,(b) and if it is serious, when the government will take action to legislateagainst firework displays in Victoria Harbour.The following two steps can help you complete the task no matter which role you play.1.Decide what kinds of data are relevant and useful. You may collect the data by means ofan Internet search.Dates of firework display held in recent 08,1/10/20091/10/20101/10/2007,Points to consider:(a) What air pollutants are considered in calculating the API?(b) What chemicals released from fireworks are the air pollutants involved in thecalculation of API?(c) Which API, general or roadside, should be used for analysis?(d) Which district’s air pollutant data should be used for analysis?(e) How many sets of data should be collected (only for the day of firework display orthe day of firework display 1, 2, 3 days) for analysis?(f) What meteorological data need to be considered?Student Handout – E1(NP)page 2 of 3
Integrated ScienceSample SBA Task2.There are a lot of numerical data to handle. Plotting graphs will help you analyse andinterpret the data. Decide what types of graphs you should ironmentinhk/air/air pastapi/pastapie.php (useful past API records)http://epic.epd.gov.hk/ca/uid/airdata/p/1 (useful past Air Quality Monitoring data)http://www.hko.gov.hk/ENDStudent Handout – E1(NP)page 3 of 3
Integrated ScienceSample SBA TaskNon-Practical Related Task E2Influenza and Our HealthStudent HandoutInfluenza is a respiratory infection caused by several influenza viruses. Most people whoget influenza recover in about one week. However, influenza and its complications can belife-threatening for elderly people, newborn babies and people with chronic illnesses.In this assignment, you are required to do the following:1.2.3.Study information on influenza from six different sources (A to F) and answer thequestions after the sources. The questions may help you produce the multi-mediaartefact in 2. You can find more information about influenza in the library and fromthe Internet.Produce a multi-media artefact (e.g. PowerPoint slides or web page) to introduce to yourclassmates: how viruses that cause human flu, avian flu and human swine flu are classified andnamed; how medicines (e.g. Tamiflu) help in treating influenza; why vaccination sometimes cannot help; and the scientific principles of some measures/practices commonly adopted to preventpeople from contracting influenza.Give a 5-minute oral presentation of the multi-media artefact produced.Source A: An article “The Flu Types – Seasonal, Pandemic, Avian (Bird), Swine” from theweb page of National Institute of Allergy and Infectious standingflu/pages/definitionsoverview.aspx)Source B: Diagrammatic representation of a flu virusStudent Handout – E2(NP)page 1 of 4
Non-Practical Related TaskQ1. How is the classification of influenza viruses related to the structure of a virus?(2 marks)Q2. What type of influenza virus caused the avian flu in Hong Kong in 1997?(1 mark)Q3.Virus causes harm by infecting living cells, multiplying within them and ruining themto form and release new viruses. The cycle then repeats itself. How do differentparts of an influenza virus enable it to infect the cells and spread inside our body?(2 marks)Q4.Describe how new strains of influenza viruses develop.(4 marks)Source C: A table showing the effect of three kinds of treatment on preventing influenza,treating influenza and easing influenza symptoms.TreatmentPrevent influenzaTreat influenzaEase influenzasymptomsAntiviral medicines(e.g. Tamiflu) Influenza vaccines Antibiotics Q5.According to Source C, should people suffering from influenza use antibiotics fortreatment? Briefly explain.(2 marks)Q6.Tamiflu belongs to the class of medicines called neuraminidase inhibitors.Tamiflu help in treating influenza?How can(2 marks)Q7.Would vaccines specifically designed to prevent H3N2(Brisbane) infection also helpprevent H1N1(Brisbane) infection? Briefly explain.(2 marks)Source D: A 2-minute animation “Influenza” from the web page of the Virtual umanatlas1/vmc white.asp?anid 0163)Student Handout – E2(NP)page 2 of 4
Integrated ScienceSample SBA TaskSource E:The chain of infectionThe Chain of Infection shown below provides a model for understanding how any infection isspread. All of the components in the chain must be present for an infection to occur.Infectious agent is the micro-organism that causes infection, e.g. bacteria, viruses, fungi, etc.Reservoir is the place where micro-organisms live, e.g. humans, plants, animals, food, air, soil,water, etc.Portal of exit is how micro-organisms leave the reservoir, e.g. excretion, secretion, droplets, etc.Means of transmission is how micro-organisms move from place to place, e.g. air borne, bloodborne, water borne, direct contact, etc.Portal of entry is how the micro-organisms enter the host, e.g. inhalation, ingestion, broken skin,etc.Susceptible host is a person who may become infected, e.g. children, the elderly, men, women, etc.Source F:PowerPoint slides produced by the Central Health Education Unit titled, How toPrevent Influenza (slides 29 to 43) (Appendix A) (Available at:http://www.info.gov.hk/info/flu/eng/files/HOW TO PREVENT INFLUENZA en 20051028.ppt)Q8.With reference to Source E, suggest how Tamiflu helps in controlling the spread ofinfluenza.(1 mark)Q9.To combat the highly pathogenic avian flu in 1997, all poultry in Hong Kong werekilled, and poultry farms and markets were closed in December 1997. How did thesemeasures help control the spread of the disease?(1 mark)Student Handout – E2(NP)page 3 of 4
Non-Practical Related TaskQ10. With reference to Source D, state the mode of transmission and the portal of entry ofthe influenza virus respectively. Suggest how the chain of infection (illustrated inSource E) can be broken at means of transmission, portal of entry and susceptible hostwith good practices of personal hygiene and healthy lifestyle suggested in Source F.(6 marks)ENDStudent Handout – E2(NP)page 4 of 4
Appendix AAppendix AStep 3 : Keep Hands CleanWhen Should We WashOur Hands?如何防備流感Before touching eyes, mouth & noseWhen hands are contaminated byrespiratory secretione.g. after coughing / sneezing After touching public installationsor equipmente.g. escalator handrails,elevator control panels,door knobs Before handling food or eating After going to toilet HOW TO PREVENT INFLUENZA 衞生署中央健康教育組Central Health Education UnitDEPARTMENT OF HEALTHOctober 2005Step 3 : Keep Hands CleanStep 3 : Keep Hands CleanSteps to Good Hand Washing : Wet hands under runningwaterApply liquid soap and rubhands together to make asoapy latherMassage all the fingersproperly for at least 20secondsThe tap may be turned off byusing the towel wrapping thefaucetNote: Rub hands with 65 95% alcoholhandrub to disinfect them whenhand washing facilities are not availableRinse hands thoroughlyunder running waterStep 4 : Use Mask Properly Dry hands thoroughly withclean cotton towel / papertowel / hand dryerA way to prevent spread ofrespiratory tract infectionsStep 4 : Use Mask Properly People who shouldwear masks:outward InwardSurgical masks preventspread of droplet infectionsPatients with respiratoryinfection symptoms Caregivers of patients withrespiratory infectionsymptoms Visitors of clinics or hospitals 1
Step 4 : Use Mask ProperlyStep 4 : Use Mask ProperlyPoints to note about wearing a surgicalmask :Points to note about wearing a surgicalmask : After taking off the mask, put the mask into aplastic or paper bag before putting it into arubbish bin with a lid A surgical mask should be changed at leastdaily Replace the mask immediately if it isdamaged or soiled The mask should fit snugly over the faceTry not to to
Integrated Science . School-based Assessment Sample Tasks . experiment can be improved. (3 marks) Student Handout (NP) page 3 of 7 . Integrated Science Sample SBA Task; Q9. Suppose that Mary wears a pair of sports shoes with air cushions and repeats the . An article on oil spill off the coast of South Korea in December, 2007 .
