Who do you think _ the first to come into the room to clean it?A.was B.to be C.being D.of being
问题描述：
Who do you think _ the first to come into the room to clean it?A.was B.to be C.being D.of being
答
A.was
do you think是插入语,去掉它,就明白了：Who （ was ） the first to come into the room to clean it?为什么是过去式？说话时，clean的动作已经过去了