问题
选择题
You can't watch TV _____ you finish your homework. [ ]
A. before
B. if
C. while
D. as
答案
答案:A
You can't watch TV _____ you finish your homework. [ ]
A. before
B. if
C. while
D. as
答案:A
因测试需要,一辆汽车在某雷达测速区,沿平直路面从静止开始匀加速一段时间后,又接着做匀减速运动直到最后停止.下表中给出了雷达测出的各个时刻对应的汽车速度数值.求:
时刻/s | 0 | 1.0 | 2.0 | 3.0 | 4.0 | 5.0 | 6.0 | 7.0 | 8.0 | 9.0 | 10.0 |
速度/m•s-1 | 0 | 3.0 | 6.0 | 9.0 | 12.0 | 10.0 | 8.0 | 6.0 | 4.0 | 2.0 | 0 |
(2)汽车在该区域行驶的总位移x是多少?