如图所示，相距为d的两平行金属板的电容为C，带电量为Q．有一长为L的绝缘轻杆，两端各固定电荷量分别为—q和+q的小球，不计两球的重力和两球间的库仑力．现先将杆从平行于极板的位置I缓慢移动到垂直于极板的位置Ⅱ，再从位置Ⅱ缓慢移动到无穷远处．则（ ）
A．从位置I移到位置Ⅱ的过程中，两球电势能之和减小
B．从位置I移到位置Ⅱ的过程中，电场力做功为零
C．从位置Ⅱ移到无穷远处的过程中，两球的电势能之和不变
D．从位置Ⅱ移到无穷远处的过程中，克服电场力做功
AD
从位置I移到位置Ⅱ的过程中，电场力对+q做正功，对-q做负功，且做的正功较大，电场力做功
，所以电视能减小，故A正确，B错误
从位置Ⅱ移到无穷远处的过程中，克服电场力做功，C错误D正确
故选AD
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请按汤姆某一天的作息时间表，在短文后的空格处填上恰当的词。
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| My name is Tom. I'm an American boy. I study at No.2 Junior High School. I 1 at six o'clock in the morning today. I 2 at six fifty. I 3 at seven fifteen. School begins(开始) at eight o five. I have lunch 4 . I go to the old man's home and help him carry water at 5 in the afternoon. I 6 at three fifty. I go to Miss Li's home at 7 in the afternoon. I go home at 8 . I 9 at seven ten in the evening. I often 10 at half past eight. I go to bed at nine forty. 1. ______2. ______3. ______4. ______5. ______ 6. ______7. ______8. ______9. ______10. ______ | ||||||||||||||||||||||||||||