A:Why don’t play concentration games?
B:One thing you could do is play concentration games.
C:What about to play concentration games?
D:It might be a good idea playing concentration games.
用直尺和圆规作一个角等于已知角的示意图如下,则说明∠A′O′B′=∠AOB依据是( )
甲、乙两车在同一水平公路上沿同一方向做直线运动,某时刻起,甲以初速度v甲=16m/s,加速度大小a甲=2m/s2做匀减速直线运动,同时在甲后面x0=26m处,乙以初速度v乙=4m/s,加速度a乙=1m/s2做匀加速直线运动.求: