—How many times have you been to China?
—In fact, it is the first time that I__________ here.
| A．was | B．have been | C．had been | D．am |
—John，when shall we meet again，Thursday or Friday?
—．I'll be off to London then．
| A．Either | B．None | C．Both | D．Neither |
What an unforgettable experience! I'll write it downit is still fresh in my memory．
| A．since | B．while | C．after | D．until |
—Do you think I should accept his invitation，Jim?
—．If I were you．I certainly would．
| A．None of your business． | B．It depends． |
| C．Why not? | D．I don't think so． |
He called to tell me that you are in hospital, otherwise I ______ nothing about it.
| A．had known | B．wouldn’t have known |
| C．would know | D．would have known |
Living in the mountain area has its problems , _____ obtaining water is a big problem.
| A．of which | B．for what | C．as | D．whose |