What would you do if _________ eighty-year-old man fell down in front of you? —-I don’t know. Maybe I will help him.

Of the stars , the sun is _____ to the earth.

Do you like junk food ?—Yes, I love hamburgers very much. I often eat .

If our government _______ attention to controlling food safety now, our health _______ in danger.

What kind of movies do you like?— I like the movies ____ are about Chinese history.