如图所示，R是一放射源，虚线框内有匀强磁场B，LL’是一厚纸板，MN是荧光屏．实验中，发现在荧光屏O、P两处有亮斑，则此时磁场方向和到达O、P点的射线与实验相符的是（）．
A.A
B.B
C.C
D.D
参考答案：C
解析：
由于α射线的贯穿本领很小，不能穿透厚纸板，所以到达O、P两位置不可能的是α射线．另外，当磁场垂直纸面向里时，由左手定则可判定β粒子向下偏转，故只有选项C正确．
根据对话内容，从A—G七个选项中选出五个能补全对话的最佳选项。（有两项多余） Lily: Hi, Jim! How was your party? Jim: It’s wonderful! 小题1: Lily: I’m sorry. I had planned to, but I had a high fever that day. Jim: Sorry to hear that. Are you all right now? Lily: Yes, thanks. 小题2: Jim: Well, we had many different kinds of food, such as chicken, pizza, salads … Lily: Did you have a birthday cake? Jim: 小题3: Lily: What about music? Jim: It was great! As you know, Linda’s brother is a famous DJ, so she brought lots of good CDs with her. 小题4: we had an unforgettable time. Lily: What time did the party end? Jim: 小题5: I couldn’t get up the next day. Lily: Well, it sounds as if you enjoyed yourselves. Jim: Yes. I like having parties because they can make us happy and relaxed.
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