问题
选择题
267. After throwing the lamp against the wall and turning over the dining room table, she deeply ______ her temper.
A．regretted losing
B．regretted being lost
C．regretted to lose
D．regretted to be lost
答案
答案：A
点开始做半径为R1的匀速圆周运动，在B点与另一电荷量为q2的静止带电粒子碰撞后合为一体做半径为R2的匀速圆周运动，如图所示，已知R1="2" R2，不计粒子的重力，忽略两粒子之间的静电力的影响，则（ ）