They were busy ________ an experiment when I came.
#92445
A
doing
B
to be doing
C
with doing
D
to do
推荐题目
Sometimes ________ English is quite different from _______ English in many ways.
#94078
A
speaking, writing
B
spoken, written
C
speaking, written
D
spoken, writing
great help, I could get rid of all the difficulty and succeeded in the end．
#88669
A
Offered
B
Having offered
C
Being supplied
D
Having supplied
Now that there are still some problems remaining ______, we have to work extra hours tonight
#91164
A
solved
B
solving
C
to be solved
D
to solve