An ecosystem consists of the living and nonliving things in an area ________ interact with one another.
| A．that | B．where | C．who | D．what |
“Why was a special meeting called?” “______ a new chairman.”
| A．Choose | B．Choosing | C．To choose | D．Chosen |
Finding her car stolen, _______.
| A．a policeman was asked to help | B．the area was searching thoroughly |
| C．it was looked for everywhere | D．she hurried to a policeman for help |
A cook will be immediately fired if he is found _______ in the kitchen.
| A．smoke | B．smoking | C．to smoke | D．smoked |
We looked everywhere for the keys, but they are nowhere _______.
| A．to find | B．to have found | C．to be found | D．being found |
He was reading his book, completely _______ to the world.
| A．lost | B．losing | C．to lose | D．to have lost |