___in the air, this kind of steel become harder and harder.
| A．Cooling | B．Having cooled | C．Being cooled | D．Cooled |
The poor children are looking forward to _____ a Christmas present that day.
| A．give | B．be given | C．giving | D．being given |
With so much work on hand, you ________ to see the game last night.
| A．mustn’t go | B．could have gone |
| C．shouldn’t go | D．shouldn’t have gone |
Perhaps I’m not quite fit for the job, but ________, please let me. have a try.
| A．somehow | B．anyway |
| C．therefore | D．though |
Happily for Johns mother, he is working harder to ______ his lost time.
| A．make up for | B．keep up with |
| C．catch up with | D．make use of |
Apple and Microsoft _______ with each other for the world market to sell more PC with their own free software.
| A．compare | B．compete | C．fight | D．deal |