---I’ve got to go now. ---Must you? I ______ you could stay for dinner with us tonight.
-Tomorrow is Sunday. Are you going swimming? -I’m not sure. It ______ the weather.
-Tina, you didn’t come to school yesterday. ______? -I had a high fever.
-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.