Tell the boy to ______ all lights as he leaves the room.
| A．take off | B．switch on | C．switch off | D．turn on |
—Is your husband good at cleaning up the room?
—Not very，but when it ________ cooking，he is much better than I am.
| A．talks about | B．refers to |
| C．comes to | D．deals with |
I think Jack will ________ a good monitor，so I’d like to vote for him.
| A．turn | B．change |
| C．make | D．elect |
The little boy was so careless with his spelling that he often ________ letters from words.
| A．left out | B．left behind |
| C．left off | D．let alone |
Evidence obtained from observation and experiment is often used to ________ a scientific theory.
| A．confirm | B．claim |
| C．conclude | D．calculate |
．Faced with a problem，you have to ________ it first，and then try to find a solution.
| A．resemble | B．substitute |
| C．concentrate | D．analyze |