问题

We_______onitforseveralhoursbutwehavenotyetreachedanyconclusion
A:work
B:areworking
C:havebeenworking
D:havebeenworked
B:areworking
C:havebeenworking
D:havebeenworked
正确答案是:
同类题型
— I have got a headache. — No wonder. You ______ in front of that computer toolong.[ ]
ze,you guy! _______ , and I’ll shoot you.” an old man with a gun in hand shoutedat me.
.—Have you finished your fashion design—Not yet. I’ll finish it if I__ten more minutes.
Look!________little animals can eat________much food[ ]
With temperature ________ so rapidly,we could not go with the experiment. [ ]