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

By the end of this term, we （ ） 3000 English words in all.

I’m not used to （ ） in that impolite way.

Constant showers are characteristic （ ） the summer here.

_____ with the developed countries, some African countries are left far behind in terms of people’s living standards.

He （ ） by his sister at that moment.

We mention the importance of giving up smoking once and again, but hardly ______ it.

Whenever we planned our vacations， mother could always offer some _____ suggestions.

Advertising is distinguished from other forms of communication （ ） the advertiser pays for the message to be delivered.

On no account （ ） to deprive(剥夺) a student of his right to receive education.

As I am sure Jenny is very honest, I （ ） she stole the money.

The department head insisted that he _____ absolute authority to regulate office work.