I think this software is of little use to your work. It is really a ________ of money.
| A．lack | B．load | C．question | D．waste |
Ladies and gentlemen, please fasten your seat belts. The plane _________.
| A．is taking off | B．takes off | C．has taken off | D．will be taken off |
Stephen Hawking believes that the earth is unlikely to be the only planet _life has developed gradually.
| A．that | B．where | C．which | D．whose |
---- An ant has two stomachs --- one for itself and the other for others.
----Really? Quite interesting. I ________ anything about it.
| A．don’t know | B．hadn’t known | C．haven’t known | D．didn’t know |
Scientists say it may be one year or so ________ it is possible to test the new medicine on human patients.
| A．when | B．after | C．before | D．since |
It is reported that 70% of people in China are ________ about the food security situation after so many accidents.
| A．curious | B．concerned | C．cautious | D．certain |