If we _______ now to protect the environment, we'll live to regret it.
_________school work, I spend most of my spare time singing and dancing.
My brother has been preparing carefully for the English exam, so that he can be sure of passing it at his first _______
——How long will you stay in Peking University? —— I don’t know. ________.
. Use your head, you’ll have an idea.
There are students in our schoo1.