17..In the United States, bus travel doesn't cost much as train travel, ?
18.
| A．don't they | B．does it | C．do they | D．doesn't it |
______ some of the questions ______,the man said good-bye to us.
| A．Leave;unanswered | B．Leaving;unanswered |
| C．Left;to be answered | D．Leaving;unanswering |
Everything ______ into consideration,they ought to have another chance.
| A．to take | B．taken | C．to be taken | D．taking |
It is said that the corporation in______charge of him is in______debt now.
| A．the;the | B．/；/ | C．/；the | D．the;/ |
.—I can’t understand him well.
—He’s not very good at getting his meaning ______.
| A．off | B．across | C．up | D．down |
Please______the numbers and I’m sure they will ______more than 2000.
| A．add;add up | B．add up;add up |
| C．add up;add up to | D．add;add up |