——Why is the classroom so dirty?——Sorry, Sir. It _____ yesterday. We forgot to do it.
#41937
A
doesn’t clean
B
didn’t clean
C
isn’t cleaned
D
wasn’t cleaned
推荐题目
——Did you go to Jack’s birthday party? ——No, I _________. 
#39542
A
am not invited
B
wasn’t invited
C
haven’t invited
D
didn’t invite
The door is __________.Who ______ it?
#42718
A
open; opened
B
open; open
C
close; closed
D
closed, close
—Excuse me, Mum. When can we have dinner? —Not until it   in half an hour.
#36824
A
is prepared
B
has been prepared
C
will be prepared
D
was prepared