根據(jù)要求改寫句子和填空。
1. We had a maths exam yesterday. (對劃線部分提問)
_____ _____ you _____ yesterday?
2. I want to get another piece of cake. (保持原意，改寫句子)
I _____ ______ to _____ _____ _____ piece of cake.
3. The snow was very heavy yesterday. (改為同義句)
_____ _____ very _____ yesterday.
4. He'll buy some school things tomorrow. (改為否定句)
He ______ ______ ______ school things tomorrow.
