把这句话（英文）改成全部否定 改怎么改
问题描述：
把这句话（英文）改成全部否定 改怎么改
He knew that the church had many secret rooms and that not all of them were safe.
他知道这教堂里有许多秘密的房间,并不是所有的房间都安全.
答
He knew that the church had many secret rooms and that none of them was safe.