旅游载客汽车使用年限为()。
A、8年
B、10年
C、15年
D、无期限
参考答案:B
They tried to ____ hard plastics for metals in manufacturing machine parts. [ ]
A. replace
B. substitute
C. take the place of
D. give way to
You are running a fever . You ____ to see the doctor .
A.need go
B.must have gone
C.should go
D.can go