– What do you think Sally will be when she grows up?– She loves science so much. I think she'll be an .
A:engineer
B:actor
C:English teacher
t=0时刻一质点开始做初速度为零的直线运动,时间t内相对初始位置的位移为x. 如图所示, xt 与t的关系图线为一条过原点的倾斜直线.则t=2s时质点的速度大小为( )
对“蒙辞以军中多务”一句的译写,最恰当的一项是( )