.
— Why was Professor Johnson unhappy those days?
— Can’t you see it clearly? The only reason was that the theory he stuck to________ wrong.
| A．proving | B．being proved | C．proved | D．was proved |
If you really have to leave during the meeting, you’d better leave ____ the back door.
| A．for | B．by | C．across | D．out |
Let’s learn to use the problem we are facing ________ a stepping-stone to future success.
| A．to | B．for | C．as | D．by |
The house still needed a lot of work, but _______the kitchen was finished.
| A．instead | B．altogether | C．at once | D．at least |
Modern equipment and no smoking are two of the things I like ____ working here.
| A．with | B．over | C．at | D．about |
I like Mr. Miner’s speech; it was clear and ______ the point.
| A．at | B．on | C．to | D．of |