A、B、C三个物体在东西向的直线上做匀变速运动，设向东为正方向，已知它们的初速度及加速度分别为v0A=1m/s，aA=1m/s2，v0B=2m/s，aB=-2m/s2，v0C=-3m/s，aC=-3m/s2，由此可知（ ）
A．A、C物体作匀加速运动，B物体做匀减速运动
B．A物体做匀加速运动，B、C物体做匀减速运动
C．C物体初速度最大，速度变化最慢
D．相同时间内A物体速度变化最小，C物体速度变化最大
A、B：A的初速度和加速度都为正值，方向相同，做匀加速．B的初速度为正值，加速度为负值，方向相反，做匀减速运动．C的初速度和加速度都为负值，方向相同，做匀加速运动．即A、C物体作匀加速运动，B物体做匀减速运动．故A正确、B错误．
C、速度和加速度的正负表示方向，不比较大小，有数据可知，C的初速度最大，加速度也最大，加速度大表示速度变化快．故C错误．
D、由于A的加速度最小，C的加速度最大．故相同时间内A物体速度变化最小，C物体速度变化最大．故D正确．
故选AD．
| 完形填空。 | |||
| Tom had a beer in a bar and he was asked to pay $6.50 by the boss. "But I paid you just now. Don't you __1__ ?" Tom replied. "OK," said the boss, "If you said you paid, you did. " Then Tom __2__ the bar excitedly. When he met his friend, Jim, he told Jim his __3__ about what had just happened to him. "The boss of the bar doesn't have a good memory. He __4__ remember whether his customers have paid or not. Why not go to the bar and have a __5__ beer?" Tom suggested. To Jim, it sounded like a __6__ idea. He rushed into the bar,ordered two beers and later played the same trick (伎俩) on the boss. Jim paid __7__ for his beer. Soon, John heard Tom and Jim's stories. He didn't want to miss the chance to try his __8__. So John hurried into the bar. When he was drinking, the boss said, were drinking beer. Neither paid, __8__ both said that they had. The next guy who tries that trick will be __9__out of the window. " "Don't tell me about your problem," John said. "Just give me my change and I'll be on my way home. | |||
| ( ) 1. A. understand ( ) 2. A. left ( ) 3. A. book ( ) 4. A. mustn't ( ) 5. A. free ( ) 6. A. strange ( ) 7. A. everything ( ) 8. A. truth ( ) 9. A. if ( ) 10. A. paid | B. remember B. set B. boss B. must B. cheap B. boring B. nothing B. result B. so B. broken | C. expect C. repaired C. wine C. can't C. fresh C. good C. anything C. luck C. or C. thrown | D. suppose D. began D. story D. can D. favourite D. stupid D. something D. experiment D. but D. looked |