离心式送风机调节门一般安装在（）。
A、进风口前面；
B、出风口后面；
C、在进风口前面和出风口后面；
D、不一定.
参考答案：A
–Could you meet me at the airport?
--I’d like to, but I’m afraid I_________ a very important meeting when you return.
A．will have attended
B．was attending
C．am attending
D．will be attending
He insisted everyone here _____ teachers' instructions. [ ]
A. had followed
B. followed
C. should followed
D. follow
