One theory, ________ suggested by Harvard University, is that humans began cooking their food, thereby releasing nutrients locked in the raw food and reducing the time needed to chew it.
| A．which | B．as |
| C．that | D．what |
—Sorry，sir，your car isn't ready yet.
It ________ by our workers.
—Oh，my God，when can I come to fetch it?
| A．is repaired | B．has been repaired |
| C．is being repaired | D．will be repaired |
If their marketing plans succeed，they ________ their sales by 20 percent.
| A．will increase | B．have been increasing |
| C．have increased | D．would be increasing |
The wet weather will continue tomorrow when a cold front ________ to arrive.
| A．is expected | B．is expecting |
| C．expects | D．will be expected |
We first met on a train in 2010，but we both felt immediately that we ________ each other for years.
| A．knew | B．have known |
| C．had known | D．know |
—I'm sure Andrew will win the first prize in the final.
—I think so.He ________ for it for months.
| A．is preparing | B．was preparing |
| C．had been preparing | D．has been preparing |