以适当的形式填空。
1. Mary and Joe go to the Shopping Center ___________ .
a. once a week b. in a week c. next week d. for a week
2. Be quiet! The baby ________ (sleep)in the next room.
3. Dick will pass the message on to your sister as soon as he ______ (meet)her in her office tomorrow.
4. The bell for the class rang while they ___________ (play)on the playground.
5. Lucy said it ___________ (rain)later on.