It ________ her four hours_________ the work yesterday.
-Are you going to Beijing by ______ train? -No. I’m taking ______ car.
There ________ elephants if we don’t protect them now.
Sara kept the secret to ________ and nobody knew about it.
The students in our school have ________ days off and spend _________ time doing their homework.
When it grows ________, it will grow ________ a strong animal.