题干
补全对话。
A: Hello! How are you?
B: ____
A: I'm fine, too. Thank you.
B: What's in your hands?
A: ____I want to go to the library. ____
B: I can show you.
A: That's good.
B: Look! ____
A: Thank you. See you!
B: ____
A. You're welcome. See you! B. Some books. C. Where's the library? D. Here it is. E. I'm fine, thanks. And you? |
答案(点此获取答案解析）
E,B,C,D,A
时刻导线框的上边恰好与磁场的下边界重合(图中位置I)，导线框的速度为
经历一段时间后，当导线框的下边恰好与磁场的上边界重合时(图中位置II)，导线框的速度刚好为零。此后，导线框下落，经过一段时间回到初始位置I。则