—_______when has the country been open to international trade?
— 1978,I suppose.
| A．Since | B．In | C．From | D．After |
— Who is the letter you are reading from, Jack?
— Well, if you know, it’s from my girlfriend.
| A． must | B．may | C．can | D．should |
Though it took him long to physically recover from the accident, it was only a short timehe became positive in spirit.
| A．while | B．before | C．after | D．when |
—How are the peace talks between the two countries?
—We are looking forward to hearing the final.
| A．competition | B．appeal | C．influence | D．outcome |
After the flood, all the emergency workersaround the clock in case the dam burst.
| A．set aside | B．stood by | C．put forward | D．came up |
—Is the chemistry experiment easy? —______. I’ll just do my best.
| A．I think so | B．Certainly | C．Not a little | D．Anything but |