Most experts agree that human activities such as the clearing of large areas of forests, and farming on a large scale _________ the problem of global warming.

He stayed up too late every night,______ to catch up with his classmates.

All his money had been ______,so he had to make a living by begging.

I don’t think this jacket _______ you and that your hat _______ this jacket perfectly.

Don’t _________ any letter in the word, or it will be a wrong word.