某研究性学习小组的同学在学习铁及其化合物知识时进行了系列研究．

如图所示，一足够长的木板静止在光滑水平面上，一物块静止在木板上，木板和物块间有摩擦．现用水平力向右拉木板 ，当物块相对木板滑动了一段距离但仍有相对运动时，撤掉拉力，此后木板和物块相对于水平面的运动情况为(　 　)

Dear editor,

    I am not a good-looking boy and I'm not good at studying, either. Some people don't even want to talk to me. So I usually feel lonely. Sometimes I think that if I wanted to leave home, nobody would care. How can I stop feeling like this?

Peter

Dear Peter,

    Without knowing more about you, it is hard for me to give you some good advice.

    But first, I am sure that you are wrong that nobody would care if you left home. What about your parents? And other family members? It seems that you are very sad. You'd better go to see a doctor or talk to your parents. They will be able to help you.

    Secondly, I'm sure there is someone in your class who feels lonely, too. You never know how other people feel inside. Try to make friends with them.

    Or you may join a club to meet new people and to keep yourself busy.

    You need to find happiness in yourself. Write a list of all the good things about yourself, learn to like yourself, and then others will see your confidence and like you, too.

Editor