The reason ____ he was late for school was _____he had to send his mother to a hospital

Are you going to take part in the English speaking contest —_______. It’s too good an opportunity to miss.

Now that you like the personal computer very much, isn’t it a good idea to get one?-Well, I’d like to but I can’t afford _____ computer at present.

he development of science and technology, the prices of TV sets have ________

He has ____________ himself to be innocent (无罪的).