问题 多选题
如图所示,一束电子以大小不同的速率沿图示方向飞入横截面为一正方形的匀强磁场区,在从ab边离开磁场的电子中,下列判断正确的是(  )

A.从b点离开的电子速度最大

B.从b点离开的电子在磁场中运动时间最长

C.从b点离开的电子速度偏转角最大

D.在磁场中运动时间相同的电子,其轨迹线一定重合

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For the people who have never traveled across the Atlantic the voyage is a fantasy. But for the people who cross it frequently one crossing of the Atlantic is very much like another, and they do not make the voyage for the (56) of its interest. Most of us are quite happy when we feel (57) to go to bed and pleased when the journey (58) . On the first night this time I felt especially lazy and went to bed (59) earlier than usual. When I (60) my cabin, I was surprised (61) that I was to have a companion during my trip, which made me feel a little unhappy. I had expected (62) but there was a suitcase (63) mine in the opposite corner. I wondered who he could be and what he would be like. Soon afterwards he came in. He was the sort of man you might meet (64) , except that he was wearing (65) good clothes that I made up my mind that we would not (66) whoever he was and did not say (67) . As I had expected, he did not talk to me either but went to bed immediately.
I suppose I slept for several hours because when I woke up it was already the middle of the night. I felt cold but covered (68) as well as I could and tried to go back to sleep. Then I realized that a (69) was coming from the window opposite. I thought perhaps I had forgotten (70) the door, so I got up (71) the door but found it already locked from the inside. The cold air was coming from the window opposite. I crossed the room and (72) the moon shone through it on to the other bed. (73) there. It took me a minute or two to (74) the door myself. I realized that my companion (75) through the window into the sea.

A. had to jump B. was to have jumped
C. must have jumpedD. could be jumped