We teachers should ______ students ______ us questions in class. 
#48995
A
be allowed, to ask
B
let, to ask
C
encourage, to ask
D
allow, ask
推荐题目
The police warned the children __________the football in the street.
#50675
A
don’t play
B
not play
C
to not play
D
not to play
I hear the birds _______.
#51349
A
sing
B
to sing
C
sings
D
singing