Question

14．Children who spend more time outdoor may have a lower risk of becoming near-sighted，new research suggests．
   In the study，researchers looked at about 1，900 schoolchildren in China．The scientists found that the kids who had been instructed to spend more time outdoors over three years were 23 percent less likely to develop near-sightedness during this time than those who had not been instructed to spend more time outdoors．Moreover，among the kids who did become near-sighted during the study，the degree to which their eyesight worsened was slightly smaller among those who spent more time outdoors．
   In the study，the researchers selected six schools and required the children，whose average age was 7 at the start of the study，to attend one additional 60-minute class of outdoor activities during each school day for three years．The parents of these children were also encouraged to engage（使参加） their children in outdoor activities after school，especially during weekends and holidays．The other half of the children，from another six schools，continued their usual activity patterns．
   After three years，30.4 percent of the kids in the intervention（干预） group had become near-sighted，compared with 38.5 percent of the kids in the control group，the researchers found．
   The reduction in the risk of near-sightedness found in the study is important，because children who develop near-sightedness at a young age are most likely to develop worse myopia （the medical term for near-sightedness） later on，the researchers said．
It is not clear exactly why spending more time outside would benefit children's eyesight．However，some research has suggested that the higher levels of light intensity found outdoors may increase the release of the chemical dopamine from the retina（视网膜） of the eye，which is beneficial to eyesight．In turn，dopamine is known to inhibit the type of growth in the eye that is associated with myopia．
Based on the new results，the researchers recommend that children spend more time outdoors because of the potential benefits to their eyesight．However，it's important to protect kids'skin and eyes from UV light，which can be damaging．
28．What is the main idea of the passage？A
A．Parents should engage children in outdoor activities．
B．Kids who often play outside may have better eyesight．
C．Kids are unlikely to gain weight if they usually play outdoors．
D．Recently researchers have discovered a cure to near-sightedness．
29．How many schools are involved in the study in total？B
A.3                    B.6                        C.9                        D.12
30．The underlined word"inhibit"in the last but one paragraph meansA．
A．prevent       B．cause               C．encourage                D．preserve
31．Which of the following is true according to the passage？C
A．About 1，900 seven-year-old schoolchildren have participated in the study．
B．Parents of the children in the control group were also involved in the study．
C．When playing outside，children should protect their skin and eyes from the sun．
D．Based on the results，scientists found out why staying outside benefits eyesight．

Answer 1

分析 本文属于说明文阅读，作者通过这篇文章主要向我们描述了新的研究表明，户外活动时间多的儿童患近视的风险较低．

解答 28．A．主旨大意题．根据最后一段the researchers recommend that children spend more time outdoors because of the potential benefits to their eyesight可知文章主要讲家长应该多带孩子去户外运动；故选A．
29．B．细节理解题．根据第三段 In the study，the researchers selected six schools and required the children可知总共有6所学校参与了这项研究；故选B．
30．B．词义猜测题．根据倒数第二段In turn，dopamine is known to inhibit the type of growth in the eye that is associated with myopia反过来，多巴胺是已知的抑制在眼与近视增长类型；可知意为防止；故选B．
31．C．细节理解题．根据最后一段However，it's important to protect kids'skin and eyes from UV light，which can be damaging可知玩耍时，孩子们应该保护自己的皮肤和眼睛免受阳光的伤害；故选C．

点评 考察学生的细节理解和推理判断能力，做细节理解题时一定要找到文章中的原句，和题干进行比较，再做出正确的选择．在做推理判断题不要以个人的主观想象代替文章的事实，要根据文章事实进行合乎逻辑的推理判断．