（ ） relatively costly, the engine is highly efficient and needs servicing infrequently.

By this time next week, the winners _____ their awards.

（ ） looked up in alarm.

The two companies decided to （ ） on a project concerning animal cloning.

He （ ） yesterday morning, and would stay for three days.

If you get into difficulties, don’t hesitate to （ ） help.

I gave John a present but he gave me nothing______.

Let’s read the novel together, （ ）？

Her sister always spends so much _____ her clothes that she can’t manage to live with her salary.

He studies so hard to avoid （ ） at the bottom of the class.

They were talking （ ） while preparing dinner.

He had his book () at his own expense.