He found it important _______ the situation all over the world.
A. study
B. to study
C. studies
D. to be studied
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Remember that it makes a bad _________if you are late.
A. custom
B. habit
C. comment
D. impression
The local government has always placed a strong emphasis _____ educational and vocationaltraining.
A. with
B. for
C. on
D. to
大多数活塞发动机的活塞顶为球形。
A. 对
B. 错
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