题干

一带电粒子射入固定在O点的点电荷的电场中,粒子轨迹如图中虚线abc所示,图中实线是同心圆弧,表示电场的等势面,不计重力,可以判断(   )
(1)粒子受到静电排斥力的作用       (2)粒子速度
(3)粒子的动能            (4)粒子电势能

A:(2)、(4)正确

B:(2)、(3)正确

C:只有(3)、(4)正确

D:(1)、(3)、(4)正确

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D

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    “You're leaving again?” asked my daughter as she saw me packing my carry-on.

    More than her words, it was her face that pierced (刺穿) my heart ---I could see how crestfallen she was. 

    “It's only for two nights, “I explained.

    But that didn't matter to her. It was just one more trip after barely being home for five days. I decided in that moment to travel less whenever possible and I managed to avoid flying altogether for most of the summer. As a result, it was a summer full of discoveries. I realized that my kids really were proud of me. In their time away from me they had learned lessons I couldn't have imagined.

    Recently I began traveling a lot again. But this time it was different, mainly due to the fact that I had seen firsthand that my children value strong female role models. They realize that hard work pays off. Being away from them even for a day at a time in many ways had done them a lot of good.

    In particular, being a working mom is teaching my daughter how important it is to be independent and that you can follow your dreams. In many ways, her idea of a professional woman is much more realistic than what I imagined when I was her age. I think that even at nine years old she already knows that for all the success you might achieve, there is a price to pay, whether it's long hours, spending time away from those you love, or simply not having the energy to have fun at times. I know the wishes I would devote all of my time to her, but honestly, even if I didn't work I would rather she learned not to depend on me for everything, She needs to realize that she can fly on her own --- and that isn't possible if I am hovering over her every single second of the day .

    I have also realized that having a career sets a good example for my son. He is not afraid of a strong woman, and has a great respect for them. When he's older, this will help him build healthier relationship.

    Therefore, for all the working moms out there who work long hours, remember to value the positive lessons you might be teaching your kids.