She is already 16years old. But she _______as if she were still a little girl.

This river forms a natural _______ between China and Korea.

When a spacecraft travels, one of the major problems is reentry into the Earth ’s _______.

In order to increase our output, we need to import more production _______.

We can not trust him any more because he often________ his duty.

John _______ to be a polite man. But in fact he is veryrude.

When you fill in the application form, please use your_______ address so that we can contact you easily later.

He works in our university as a visiting _______, not as a formal faculty member.

In the United States, the foreign policy is decided by the ________ government, not by each state.

We do not have a _______ school in our institute. The highest degree we provide for the students is a B. A. and a B.S. .