Unit 4 Global warming reading课时作业

Ⅰ.阅读理解(共15小题；每小题2分，满分30分)

　　A

　　Listening to music while you drive can improve your speed and ability to get away from accidents, according to Australian psychologists. But turning your car radio up to full volume could probably make you end up in an accident. The performance of difficult tasks can be affected if people are subjected to loud noise. The experience of pulling up at traffic lights alongside cars with loud music made some psychologists in the University of Sydney look into whether loud music has something to do with driving.

　　The psychologists invited 60 men and women aged between 20 and 28 as subjects and tested them on almost the same driving tasks under three noise conditions: silence, rock music played at a gentle 55 decibels(分贝), and the same music at 85 decibels.

　　For 10 minutes the subjects sat in front of a screen operating a simple machine like a car. They had to track a moving disk on screen, respond to traffic signals changing color, and brake in response to arrows that appeared without warning.

　　On the tracking task, there was no difference in performance under the three noise conditions. But under both the loud and quiet music conditions, the performers "braked" at a red light about 50 milliseconds sooner than they did when there was no rock music at all. That could mean a reduction in braking distance of a couple of meters actually, the difference between life and death for a pedestrian.

　　When it came to the arrows that appeared across the visual field, the psychologists found that when the music was quiet，people responded faster to objects in their central field of sight by about 50 milliseconds. For the people listening at 85 decibels, response time dropped by a further 50 milliseconds-a whole tenth of second faster than those "driving" with no music.

"But there's a trade­off，" the psychologists told the European Congress of Psychology. "They lose the ability to look around the whole situation effectively." In responding to objects that suddenly appeared, people subjected to 85­decibel rock music were around 100 milliseconds slower than both the other groups. Since some accidents-such as children running into the road-take place without any notice,