--- We don't know who stole the book. What's your opinion?

问题描述:

--- We don't know who stole the book. What's your opinion?
--- Tom is considered ____ it.
a. having doneb. to have donec. doingd. to do
选B 为什么?怎么判断?第2句是什么意思?

选B
被动语态,be considered to 固定搭配
have done 完成时态
意思是:人们认为是汤姆干的(偷书).