I have bought _____ useful reference books _____ I don’t know which one to start with.

You should respect others’ opinions, and at the same time you should insist on （ ） you believe is right.

I gave John a present but he gave me nothing______.

（ ） when she started complaining.

You’ve never told me why you didn’t come to my birthday party， _____?

He was never （ ） of experimenting with different ways of planting his crops.

We tried to find a table for seven, but they were all （ ）.

The engineer （ ） my father works is about 50 years old.

A loud noise （ ） my attention from cooking and everything was burnt.

I am sorry that he （ ） in such poor health.

He spoke so quickly that I didn’t_____what he said.

He learned how to use sign language to _____ with deaf customers.