A huge amount of oil was spilt on the East Sea, the causes of ______ are still under investigation.
A. it B. that C. which D. whom
--- Has James finished his report on his Enquiry Learning yet?\
---- I’m not sure. He _____ on it last week.
A. was working B. has worked C. worked D. had worked
If you are traveling_ the customs are really foreign to your own，please do as the Romans do.
A. in which B. what C. when D. where
you may have, you should gather your courage to face the challenge.
A. However a serious problem B. What a serious problem
C. However serious a problem D. What serious a problem
You can’t predict everything. Often things don’t ________ as you expect.
A. work out B. break out C. run out D. put out
The living room is clean and tidy, with a dining table already ______ for a meal to be cooked.
A. having laid B. laying C. laid D. being laid
