题目

如图4所示，实线是匀强电场的电场线，虚线是某一带电粒子通过该电场区域时的运动轨迹，a、b是轨迹上两点．若带电粒子在运动中只受电场力作用，则由此图可作出的正确判断是( ) 图4 A．带电粒子带负电荷 B．带电粒子带正电荷 C．带电粒子所受电场力的方向向左 D．带电粒子做匀变速运动 答案：CDLaws that punish parents for their little children’s actions against the laws get parents_______.A. worried B. to worry C. worrying D. worry