研究发现，长期驾车会加速大脑老化
Driving for more than two hours a day negatively affects IQ levels, scientists warned. A recent study found that long time behind the wheel could speed up the effects of age on the brain. It might come as bad news for middle-aged drivers. The results could be explained by the fact that the mind is less active on long car journeys.
The big project studied more than half a million British people aged from 37 to 73 over a time of five years. Out of these some 93,000 of them drove more than two or three hours a day. Researchers found that not only did these people have lower brainpower to begin with but their IQ score went down more rapidly over the course of the study than those who did little or no driving.
Kishan Bakrania, a medical expert, said, “We know that regularly driving for more than two or three hours a day is bad for your heart.” And this research suggests it is bad for your brain too, maybe because your mind is less active in those hours.
Previous studies have found that long time of inactivity(不活动) has a bad affect on brainpower. Dr Bakrania’s research shows similar results for those who watched more than two hours of television a day.
1.The underlined words “behind the wheel” means________.
A running
B driving
C falling
D watching
解析：选B。B 词义猜测题。根据第一段第一句，科学家称，每天开车超过两个小时会对智商产生负面影响；接下来第二句阐释长时间开车具体对哪方面产生影响，所以behind the wheel 指的是 “开车”，wheel意为“方向盘”，故选B。
2.Driving for a long time causes the brain to run slower because________.
A it makes you tired
B it kills more brain cells
C it makes the mind less active
D it makes the mind work actively
解析：选C。C细节理解题。根据第一段最后一句可知，前文说到的“加速衰老对大脑的影响”是因为长时间开车时大脑不够活跃造成的，也就是说长时间开车造成大脑不够活跃，故选C。
3.About________ people in the study drive more than two hours a day.
A 9.3%
B 18.6%
C 81.4%
D 90.7%
解析：选B。B 数字计算题。根据第二段第一、二句可知，参与调查的人有500000人，其中93000人每天开车两到三个小时以上，93000÷500000 =18.6%，因此开车时间超过两个小时的人的比重为18.6% ，故选B。
4.Which of the following statements is TRUE?
A Driving will speed up the growth of the brain.
B People can improve their brainpower by driving.
C People who do little or no driving are all clever.
D Watching TV for long can harm one’s brainpower.
解析：选D。D 推理判断题。根据最后一段最后一句可知，每天看两三个小时电视和每天开两三个小时的车有同样的效果，即长时间看电视也会造成脑力下降，故选D。
5.What is the best title of this passage?
A Driving for long has bad effects on your brain.
B People who drive for long are usually stupid.
C You can be smarter if you never drive.
D Driving for long makes you more clever.
解析：选A。A 文章标题题。文章第一段即为本文主旨句，点明了长时间开车对大脑有负面影响，全文也都是围绕这一主旨展开的，故选A。