根据要求完成句子。
1. We publish our school newspaper twice a month. (改为被动语态)
Our school newspaper ______ ______ twice a month.
2. The meeting began half an hour ago. (同义句)
The meeting has ______ ______ for half an hour.
3. I heard that she was singing at that time. (改为简单句)
I heard ______ ______ at that time.
4. My brother gave my mother a present on her birthday. (改为被动语态)
A present ______ ______ to my mother on her birthday.
5. My friend seems to be very angry. (同义句)
______ seems that my friend ______ very angry.
