______ from space, our earth, with water covering 70% of its surface, appears a “blue planet”.

Do you know what chemical ______ are involved when food is digested?

______ still believe we can resolve the problem without going to war.

— Jane, you’ve changed your hairstyle. It’s a very stylish haircut.—_________________________

Professors should ________ repeating in lectures material that is in the textbook.

He has already made up his mind. It’s no use _____ him.

I _____for the bus for the past 20 minutes and still it has not come.

Britain’s press is unusual ________ it is divided into two very different types of newspaper：the quality press and the popular press.

I was on my way to school this morning____it suddenly began to rain heavily.

In ______ of her apology, we decided to take no further action.