There was plenty of time . She ____ .
| A．needn''t hurry | B．mustn''t hurry | C．needn''t have hurried |
| D．mustn''t have hurried |
Old－fashioned phones matter when wireless networks ________ in disasters.
| A．turn down | B．turn out |
| C．break down | D．break out |
While intelligent people can often________the complex, a fool is more likely to complicate the simple.
| A．sacrifice | B．substitute | C．simplify | D．survive |
As the train ran faster and faster，the lights of the city were soon ________.
| A．left off | B．left alone |
| C．left behind | D．left out |
At the edge of the grass，there's a sign saying“________ the grass”．
| A．Keep up | B．Keep away |
| C．Keep off | D．Keep back |
Suddenly I realized that I had stayed here long and ________ to say goodbye to the host.
| A．raised | B．rose | C．lifted | D．stood |