题目

如图所示。两个质量均为m的小球A、B用轻杆连接后斜放在墙上处于平衡状态，已知墙面光滑，水平地面粗糙。现将A球向上移动小段距离，两球再次处于平衡状态，那么将移动后的平衡状态与原来的平衡状态比较，地面对B球的支持力N及轻杆对A的作用力F变化情况是  A．N不变，F变大                B．N不变，F变小C．N变大，F变大                D．N变大，F变小阅读下面短文，按照句子结构的语法性和上下文连贯的要求，在空白处填入一个适当的词或使用括号中词语的正确形式填空。What do you do after school？You may say you go home and do 1.(you)homework.But I think we can have many other things to do 2. school.We can join different 3.，like the art club and the music club.If you swim 4.(good)，you can join the 5.(swim)club.Maybe you can't play 6. violin or the guitar well，but you can learn to play 7.(they)at the music club.Then，some people there can 8.(help)you.I like 9.(book)and I often go to the reading club.Do you like books？10.(come)with me!