根据短文理解，从A、B、C、D四个选项中选择最佳答案填空。

    Hello! I'm Jane from Canada. I like my school a lot. It's not big 1 it's very nice. All my teachers and classmates are 2 to me. I love3 very much. We study English, math, art and some other 4. Some subjects are  5, but some of them are boring. Of all of them, I like 6 best, because I like drawing pictures. Oh, my favorite 7 are Tuesday and Friday. On these     8 days, we have art lessons. I don't like politics 9 it's boring and difficult.

    My friend Susan 10 at my school. I often go to school with her. She likes politics. She thinks it's easy.

在“用伏安法测电阻”的实验中，下列注意事项中，没有必要的是（　　）

请从以下7个词语中任选4个写一段话。要求语意完整，合乎情理，不超过48字。

给力 雷人 粉丝 妙趣横生 山重水复 美不胜收  怡然自得

如图所示，用粗细均匀的阻值为R的金属丝做成面积为S的圆环，它有一半处于匀强磁场中，磁场方向垂直纸面向里，磁场均匀变化，磁感应强度大小随时间的变化率为k（k>0），ab为圆环的一条直径，则下列说法正确的是（      ）