问题

Why is the classroom so dirty?——Sorry, Sir. It _____ yesterday. We forgot to do it.
A:doesn't clean
B:didn't clean
C:isn't cleaned
D:wasn't cleaned
B:didn't clean
C:isn't cleaned
D:wasn't cleaned
正确答案是:
同类题型
I want to be an English teacher ________ ten years. [ ]
I didn’t know you were friends with Mr. Smith. — We ______ each other for6 years.
Why do you prevent them______playing computer games?—Because they have a bad______on teenagers.
I like playing _____ piano.– Oh, we have _____ same hobby.
Excuse me, where __________? Do you know? Yes, I know where ________.