I won’t tell the student the answer to the math problem until he ____on it for more than an hour.
#99288
A
has been working
B
will have worked
C
will have been working
D
had worked
推荐题目
I believe that those mountains ________ with trees in a few years’ time. 
#102710
A
are covered
B
will be covered
C
are covering
D
will cover
Her forehead _____ hot. I’m afraid she is ill.
#103728
A
is feeling
B
felt
C
is felt
D
feels
The man whose songs we are fond of ____ in our city next week.
#104221
A
singing
B
to sing
C
will sing
D
sang