Be careful when you surf the Internet．If you download a virus into your computer ______, you will not open your files．

You’d sound a lot more polite if you make a request _____ a question．

It is required that the football match___________put off ________ the bad weather.

We study several subjects, __________ Chinese, maths, English and so on.

Dorothy works very hard ；she shows a very positive attitude            her work.

_________ New Year’s Day around the corner, all the salesmen were trying hard to talk customers_________ buying their goods.

Why did the project come to a stop half way?
--- It was in part ______________ financial difficulties.

Digging down into the earth is like reading _______of a book.

The topics of a travel journal can be different from a diary, often _______
people, things, and events __________ the readers.

People greatly differ __________ their views of life from each other.