请把下列句子变为被动语态
问题描述：
请把下列句子变为被动语态
The wind blew down the big tree last night.
I think that he is right.
He had not thrown the bad food.
Mother was not mending the trousers.
They would not take him to Beijing.
Nobody knew me in this town at that time.
答
The big tree was blown down by the wind last night.
He is thought to be right.
The bad food hadn't been thrown by him.
The trousers wasn't mended by mother.
He wouldn't be taken by them to BJ.
It's unknown that i was in this town at that time.