答案　B

解析　句意为：现在他20岁了，决定从他的家庭独立出来。be independent of独立于......，不依赖......。故选B项。

4．With so much free time，students who do not make good use of their time may not pass their exams.

有如此多的空闲时间，没有好好利用的学生可能无法通过考试。

make use of利用，使用

make full/good use of充分好好利用

make no use of没有利用

come into use开始使用

put...to use使用；利用

be of great use很有用

(1)We should make full use of time to study.

我们应当充分利用时间去学习。

(2)When did telephone first come into use?电话是什么时候开始使用的？

(3)They are trying to put the new tool to use.他们试图使用新工具。

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(4)This map will be very useful while you are travelling.

→This map will be of great use while you are travelling.

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(5)As we all know，every minute， full use of our lessons，will do good to our students.

A．which makes；studying B．when made；to study

C．that is made；to study D．which is made；studying