按所给首字母提示在下面短文空缺处分别填入一个适当的单词。
In the United States，children start school when they are five years old．In some states（州）they must stay in school u _______ （1）they are sixteen．M _______ （2） students are seventeen or eighteen years old when they leave middle schools．There are two k _______ （3）schools in the United States：public（公立）schools and private（私立）schools．Most children go to public schools．Their parents do not have to pay（花钱） for their education（教育）because the schools receive（得到）m _______ （4）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 still prefer（更喜欢）private schools，though（尽管）they are much more e _______ （5）．
In some ways，American middle schools are d _______ （6）from Chinese ones．In China students of one class usually stay in their classroom and their teachers come and go according to（根据）the timetable．But high school students in America go to different classrooms for different subjects，while（然而）their teachers don't m _______ （7）．
In this way the necessary（必要的）teaching facilities（设备）can be put in fixed（固定的）places，and the teachers don't need to carry them from one room to a _______ （8）．So during a ten minute break b _______ （9）classes a lot of students are hurrying in different directions（方向）to find their classrooms．
Today about half of the high school students go on to universities（大学） a _______ （10）they finish the secondary（中级的）school．A student at a state university does not have to pay very much if his parents live in that state．
Key:
1．until 2．Most 3．kinds 4．money 5．expensive 6．different 7．move 8．another 9．between 10．after
