【简答题】一质点从静止出发沿半径R=3m的圆周运动,切向加速度为3m/s2。则当t=2s时,质点的法向加速度等于( )m/s2;2s内质点经过的路程是( )m,角位移是( )rad。
【简答题】Jack (quick) ______ established himself a powerful member of the new company. (2) When she got back from the South, Susan had her car (wash) ______ thoroughly. (3) We all like your idea of using the m...
【简答题】根据短文内容,从下框A~F选项中选出能概括每段主题的最佳选项,并在答题卡上将该选项涂黑。选项中有一项为多余项。 A. Start early. B. Sing in the car. C. Attend concerts. D. Teach your child to sing. E. Show good music videos. F. Introduce your chil...