Question

8．Spending two or three hours playing outdoors each day can reduce the chance of becoming short-sighted，a research shows．It challenges the belief（信念） that short-sightedness is caused by computer use，watching TV or reading in weak light．
The Australian government researchers believe that the sunlight is good for people's eyes．They compared the vision（视力） and habits of 100 seven-year-old children in Singapore and Australia．In all，30% of the Singaporean children were short-sighted-this rate（比率） was ten times higher than Australian children．
Both groups spend a similar amount（数量） of time reading，watching television and playing computer games．However the Singaporean children spent an average （平均） of only half an hour a day outdoors-90 minutes less than the Australian children．
Professor Ian Morgan，from the Australian Research Council's vision Centre，said，"Humans are naturally long-sighted，but when people begin to go to school and spend little or no time outdoors，the number of short-sighted people gets larger．We're also seeing more and more short-sighted children in cities all around the world and the main reason may be that city children spend less time outdoors．
Daylight can be hundreds of times brighter than indoor light．But why does playing outside  prevent us from becoming short-sighted？Scientists believe that natural light has a special chemical（化学物质） which stops the eyeball from growing out of shape and prevents people from becoming short-sighted．
So be outdoors．It doesn't matter if that time is spent having a picnic or having sports．

31．How much time did the Australian children spend outdoors on average according to the  research？D
A.30 minutes．
B.60 minutes．
C.90 minutes．
D.120 minutes．
32．Which of the following is TRUE according to the passage？C
A．If people spend less time outdoors they will certainly become short-sighted．
B．There are fewer short-sighted Singaporean Children than Australian children because  they have more knowledge of protecting their eyesight．
C．There will be fewer risks of getting short-sighted if people spend two or three hours a  day playing outside．
D．When people begin to go to school they will become long-sighted．
33．What is the fifth paragraph mainly about？B
A．Why natural daylight has a special chemical．
B．Why daylight prevents people from becoming short-sighted．
C．Why daylight is much brighter than indoor light．
D．What the special chemical which can stop eyeballs from growing out of shape is．

Answer 1

分析 根据研究，澳大利亚的儿童在户外的平均时间是120分钟．如果人们一天花费两到三小时在户外玩，将减少得近视的风险．

解答 31．D 细节理解题．根据However the Singaporean childrenspent an average （平均） of only half an hour a day outdoors-90 minutes less than the Australian children．然而新加坡孩子的平均只有半个小时，比澳大利亚的孩子少90分钟，故澳大利亚儿童在户外的平均时间两小时，故正确答案为D．
32．C 细节理解题．根据Spending two or three hours playing outdoors each day can reduce the chance of becoming short-sighted，a research shows．可知如果人们一天花费两到三小时在户外玩，将会有更少得近视的风险，故选C．
33．B 主旨大意题．通读本段并据But why does playing outside  prevent us from becoming short-sighted？可知本段主要是说的日光为什么会避免人们变近视．故选B．

点评 做题时要在理解好文意的基础上，与题目有机的结合，从文章中找到相关细节性的句子与选项细细比对，进行选择或推理判断，选出符合文章内容的正确选项．做题注意灵活，有时可采用排除法或直选法确定出最终答案．