Everything on the earth ______ all the time

As we know, America is one of the most ___ countries in the world 得分：0分

As we all know, the earth ______ around the sun

As Emerson puts it,____ we travel the world over to find the beautiful,we must carry it with us or we find it not

Antarctic_____we know very little is covered with thick ice all the year round

We need friends to ________, or we will feel lonely（单选）—4分

2I didn’t know whether to ____ her silence as acceptance or refusal

8I didn’t know whether to ____ her silence as acceptance or refusal

So far as we know, the rates they ____ are among the most competitive in the line

The survival of the civilization as we know is_________ threat.

As scheduled, the communications satellite went into ________ round the earth.

As we all know, a red traffic light is often a danger ______ .