—Has Billy finished his homework today?—I have no idea.He        it this morning.
#104538
A
would do
B
was doing
C
has done
D
had done
推荐题目
He ______ in this city since he graduated from college.
#102555
A
lives
B
will live
C
has lived
D
would live
Since then the number of people taking driving lessons ________ 20%. 
#102813
A
has increased to
B
increases by
C
has increased by
D
have increased by