完形填空。

    In the United States, children start school when they are five years old. In some states they must stay in school1they are sixteen. Most students are seventeen or eighteen years old when they2secondary(中等的)schools. There are two kinds of schools in the United States: public(公立的)schools and private(私立的)schools.3children go to public schools. Their parents do not have to4their education because the schools5money from the government(政府).If a child goes to a private school, his parents have to get enough money for his schooling. Some parents still6private schools, though they are much more expensive.

    Today about half of the high school students7universities(大学)after they finish the secondary school. A student at a state university does not have to pay very much if his parents8in that state.

    But many students9while they are studying at universities. In this way they10good working habits(习惯)and live by their own hands.

下列事实中，主要与地球自转有关的是（    ）

铜片放入稀硫酸溶液中，加热，无明显现象发生。当加入一种盐后，发现铜片逐渐溶解，同时溶液慢慢变为蓝色，且有气体逸出，此盐可能是

假设你叫林洋，收到了你的笔友Susan的一封信，请你给她写一封回信。在信中回答她的问题，提出你的建议，并就此事谈谈你的看法。
Dear Lin Yang,
I have a problem these days. My mother doesn’t allow me to watch TV even on weekends. She says as a middle school student, my job is to study. After I finish my homework, she says, I should read books and watching TV is bad for me. But I think I need a rest and watching TV helps me learn a lot too.
Do you have the same problem? What do you think of my mother’s decision? What should I do?
Yours,
Susan

如图，在矩形ABCD中，以点B为圆心、BC长为半径圆弧，交AD边于点E，连接BE，过点C作CF⊥BE，垂足为F．