---I often have hamburgers for lunch.--- You’d better not. It’s bad for you _____ too much junk food.
I had useful umbrella when it rained.
Monday afternoon we rode bicycle to Georgetown.
-Do you know _________________ ? --Sorry , I don’t know .
—Tom , Don’t talk. _______ what you are doing. —Sorry, Mr. Li.
You can ______ the new words in a dictionary if you can’t understand them.