Unless ________ to answer questions, the pupils won't talk in Mrs Smith's class.
#88754
A
asking
B
asked
C
being asked
D
having asked
推荐题目
_____ his electronic dictionary made himself sad.   
#89974
A
Losing
B
Lost
C
Being lost
D
To be lost
_____ that there is no opposition , I will report it to the general manager .
#97769
A
To provide
B
Be provided
C
Having provided
D
Providing