题目

如图，一束正离子(不计重力)先后经过速度选择器和匀强磁场区域，则在速度选择器中沿直线运动且在匀强磁场中偏转半径相等的离子具有相同的( ) A . 电荷量和质量 B . 质量和动能 C . 速度和比荷 D . 速度和质量 答案：CAfter _____ the learned girl, the young man lay on his bed , wide awake with wonderful ideas _____ into his mind . [     ]A. arguing; crowding               B. arguing with; entering       C. arguing with: crowding           D. argued; entering