—Why is the classroom so dirty?—Sorry,sir. It       yesterday, We forgot to do it.
#39874
A
doesn’t clean
B
didn’t clean
C
isn’t cleaned
D
wasn’t cleaned
推荐题目
In his family           three people.
#40302
A
have
B
has
C
there is
D
there are
Everyone ______ an English story book.
#38446
A
have
B
are having
C
has
D
is have
 I hope it _________ tomorrow.
#39898
A
not snow
B
not to snow
C
doesn’t snow
D
won’t snow