.—____ when has the country been open to international trade?
—1978, I suppose.
| A．Since | B．In | C．From | D．After |
Hurry! The train _______. You know it _____at 8:30am. .
| A．leaves; leaves | B．is leaving; leaves |
| C．leaves; leaving | D．is leaving; is leaving |
With the help of high technology, more and more substances _________ in the past years.
| A．discovered | B．have discovered |
| C．had been discovered | D．have been discovered |
Jim is the only one of the policemen in his office who __________ the award.
| A．have won | B．win | C．has won | D．was to win |
The company the girl used to work ________ was shut down last month.
| A．for that | B．for | C．for whom | D．/ |
Unless __________, she won’t go to any party.
| A．inviting | B．having invited | C．invited | D．being invited |