Some plants are so difficult to grow that they can only ______ in a perfectly clean environment.
| A．communicate | B．exchange |
| C．survive | D．afford |
Glad to see you back. How long _______ in Russia?
| A．did you stay | B．have you stayed |
| C．were you staying | D．have you been staying |
When the old woman died, it___ that she was actually very rich.
| A．came to an end | B．went to light |
| C．came to life | D．came to light |
—I have a favour to ask of you.
—______.
| A．Go ahead | B．It’s a pleasure |
| C．Help yourself | D．Ask, please |
It’s reported that a bus went out of ____ control on a highway _____ east of the city and crashed into a river.
| A．the; the | B．不填; the | C．the; 不填 | D．不填; 不填 |
Medicine depends on other fields for basic information, particularly some of their specialized branches.
| A．conventionally | B．obviously | C．especially | D．inevitably |