按要求改写下列句子。
1. You must do it now. (改为祈使句)
______ ______ now.
2. They often play with the cute dog. (用yesterday改写)
They ______ the cute dog yesterday.
3. Is Lucy writing in English? (用often改写)
______ Lucy often ______ in English?
4. They are old teachers. Let us help them. (改为单数句子）
He is an old teacher. Let ______ help ______.
5. We play basketball every day. (用she来改写句子)
She ______ basketball every day.
