Read and choose

In the United States, boys and girls start school when they are five years old. In some states(州), they must stay in school until they are sixteen. Most of the students are seventeen or eighteen years old when they graduate(毕业) from secondary school. Another name for secondary school is high school. Most children go to public schools. Today about half of the high school graduates(毕业生) go on to colleges and universities. Almost half of the college students in the United States work when they are studying.

(1)In the United States, children start school at ________.

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(2)Another name for secondary school is ________.

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(3)Today ________ of the high school graduates go on to colleges and universities.

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