问题 选择题

某学校科技小组为了2008年北京奥运会场馆减弱噪声设计了如下方案,其中属于在声源处减弱噪声的是(  )

A.把场馆的玻璃做成双层

B.进入场馆周围的机动车辆禁鸣喇叭

C.在场外多栽草、多植树

D.让运动员在场馆戴上轻质头盔

答案

A、把场馆的玻璃做成双层,是在传播过程中减弱噪声;

B、进入场馆周围的机动车辆禁鸣喇叭,是在声源处减弱噪声;

C、在场外多栽草、多植树,是在传播过程中减弱噪声;

D、在场馆让运动员戴上轻质头盔,是在接收处减弱噪声.

故选B.

单项选择题

Passage OneA recent study indicates that the “short sleepers” had been more or less average in their sleep needs until the men were in their teens. But at about age 15 or so, the men voluntarily began cutting down their nightly sleep time because of pressures from school, work, and other activities. These men tended to view their nightly periods of unconsciousness as bothersome interruptions in their daily routines.In general, these “short sleepers” appeared ambitious, active, energetic, cheerful, conformist in their opinions, and very sure about their career choices. They often held several jobs at once, or work fullor parttime while going to school. And many of them had a p urge to appear “normal” or “acceptable” to their friends and associates.When asked to recall their dreams, the “short sleepers” did poorly. More than this, they seemed to prefer not remembering. In similar fashion, their usual way of dealing with psychological problems was to deny that the problem existed, and then to keep busy in the hope that the trouble would go away.The sleep patterns of the “short sleepers” were similar to, but less extreme than, sleep patterns shown by many mental patients categorized as manic.The “long sleepers” were quite different indeed. According to the study, these young men had lengthy sleeps since childhood. They seemed to enjoy their sleep, protected it, and were quite concerned when they were occasionally deprived of their desired 9 hours of nightly bed rest. They tended to recall their dreams much better than did the “short sleepers”.Many of the “long sleepers” were shy, anxious, introverted, inhibited, passive, mildly depressed, and unsure of themselves (particularly in social situations). Several openly state that sleep was an escape from their daily problems.

Many “short sleepers” are likely to hold the view that ().

A.sleep is a withdrawal from the reality

B.sleep interferes with their sound judgment

C.sleep is the least expensive item on their routine program

D.sleep is the best way to deal with psychological troubles

单项选择题