nt years, _____ problem of global warming has been very serious.—That’s right. People are facing ____ number of natural disasters now.

.When Bill Gates decided to stop schooling and created Microsoft in 1975, he ______ law at Harvard University

How old is your sister– .We had a special party for her birthday yesterday.

I’m going to spend the winter vacation in Shanghai,_______I have relatives.

Mother wanted to be a good provider, a role she ________ since her marriage to Father