To win in these areas, the firm needs a sustainable __________ advantage.
| A．competitive | B．active |
| C．attentive | D．sensitive |
--Were you in time for the meeting?
-- If I _________earlier, I would have .
| A．was told | B．had been told | C．were to be told | D．should be told |
-- I am going to Sidney for further studies next month.
-- That's fantastic. Can you keep emailing me ______ you are there?
| A．though | B．because | C．until | D．while |
The well was found __________ when we got there.
| A．digging | B．to be dug | C．to dig | D．being dug |
Tom, ________________ you from taking a hand in that affair, you ______________ in prison.
| A．if I didn’t stop; would have stayed |
| B．had I stopped; would be staying |
| C．shouldn’t I have stopped; would stay |
| D．if I hadn’t stopped; would have stayed |
The group’s research has done much toour knowledge of the HIV virus．
| A．advance | B．pull | C．rush | D．adopt |