Every 40 minutes we will take a 20-minute break, ______ your guide will give a short talk on different aspect of the Great Wall.
It is global warming, rather than other factors,_____ the extreme weather.
_____ the crisis of economy getting more and more serious, the government is searching for ways to improve people' s life.
A terrible frost hit his hometown during his sleep. The next morning he got up only .____ the outside world
--Is it convenient to you if I pay a visit to you at 10:00 tomorrow morning? --I' m afraid not. I _____ a lecture then.
The little boy sat _____ to his father and listened _______ with great interest.