Father ____ for London on business upon my arrival, so I didn’t see him.
| A．has left | B．left | C．was leaving | D．had left |
－Shall I give you a ride since you live so far away?
－Thank you.______________。
| A．It couldn’t be better. | B．Of course you can. |
| C．If you like. | D．If you are convenient. |
I _______ the dance performance many times, each giving me a new understanding.
| A．watch | B．watched | C．have watched | D．am watching |
The economic impact study was conducted by a group of _______ selected MBA students at the University of Kansas.
| A．especially | B．specially | C．regularly | D．potentially |
_______ any other species, human populations are shaped by the usual forces of natural selection, like famine, disease or climate.
| A．Compared with | B．As with | C．As for | D．In addition to |
— I’m terribly sorry to keep you waiting for so long.
— _______.
| A．Never mind. | B．That’s right. | C．You are welcome. | D．Don’t mention it. |