_____ how to express the idea in English, he turned to the dictionary.
| A．Does not know | B．Not knowing | C．Knowing not | D．Not to know |
—Have you heard that George quit his job?
—Yeah, but I can't________why he did so.
| A．put out | B．figure out |
| C．carry out | D．send out |
—Tony, you must have noticed the student who broke the glass.
—I'm sorry.I________attentively.
| A．studied | B．was studying |
| C．am studying | D．would study |
—Sorry for the delay.I got lost in the mountain.
—That's OK.You're safe and that's what________.
| A．does | B．works |
| C．stays | D．counts |
—Tom has been fired by his boss.
—________？As far as I know，he is a hardworking and considerate fellow.
| A．Why not | B．How come |
| C．What then | D．So what |
Annoyed by the salesman's bad manner，John chose ________of the two computers on sale and left.
| A．all | B．either |
| C．neither | D．none |