题干

如图所示为一种早期发电机原理示意图,该发电机由固定的圆形线圈和一对用铁芯连接的圆柱形磁铁构成,两磁极相对于线圈平面对称在磁极绕转轴匀速转动过程中,磁极中心在线圈平面上的投影沿圆弧运动(O是线圈中心),则磁铁从O到Y运动过程,经过电流表的电流方向为(     )

A:由E经电流表流向F

B:由F经电流表流向E

C:先由E经电流表流向F,再由F经电流表流向E

D:先由F经电流表流向E,再由E经电流表流向F

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答案(点此获取答案解析)

A

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                                                                                              B

    When I was a little girl, my father loved to play catch (抛接球游戏) with me. I wasn't very good, but he would encourage me. He was always telling me “keep your eye on the ball” as I would not be able to catch even the easiest of throws.

    As I got older, we didn't play catch as much. If I had a problem, I would go to my father to ask for his advice. He would try to joke with me and say “keep your eye on the ball”. We would both laugh because usually that advice did not apply to(适用于) the problem, but he would try to make me smile.

    My father became ill in 1995 when I was 23. As he suffered from a stroke (中风), he could not speak. There weren't any more conversations. He could only mouth words, which were sometimes hard to understand. After a while, I seemed to be pretty good at reading his lips (嘴唇), even better than the nurses who were caring for him.

    During our last conversation, I was telling him about a problem I was having with my then boyfriend. Once again, I could read his lips: “Keep your eye on the ball.” We both smiled.

    That was the last time I saw my father before he passed away.

    Since then, when I get into a stressful situation I tell myself “keep your eye on the ball”.