Don’t make a noise! They _______on a physics problem now.
#41516
A
will work
B
are working
C
worked
D
have worked
推荐题目
I ______ much progress in my English study since last term. 
#41652
A
make
B
will make
C
made
D
have made
--Has the match started?-- Finished! Guo Jingjing_____ it.
#42040
A
win
B
is winning
C
will win
D
won