—What do you think________ an important part in their lives?
—Pop music.
| A．plays | B．takes | C．makes | D．acts |
____ new cure for this disease that medical experts have recently developed proves to be ______ most effective, although it can not completely kill all the viruses.
| A．A; a | B．The; / | C．/; the | D．A; the |
— What made your skin look so terrible?
— _______ to the sunlight for a long time.
| A．Because it was exposed | B．After being exposed | C．Being exposed | D．Exposed |
Only after a baby seal is pushed into the sea by its mother _____ to swim.
| A．how will it learn | B．will it learn how | C．it will learn how | D．and it learns how |
As is well known, carelessness and irresponsibility _______ many deadly accidents.
| A．lead to | B．result from | C．contribute to | D．result in |
They ___________ for two hours
| A．is working | B．worked | C．have been working | D．had worked |