Mrs. Smith finds it hard to clear up the mess, as her children are alwayswhenever she tries to.
| A． | in the way | B． | on watch | C． | in sight | D． | on the line |
一____it snow tomorrow，what would we do?
一In that case，we'11 have to stay at home．
| A．Will | B．Must | C．Might | D．Should |
The world is a book，and those who don’t travel read only one page．That’s____I’ll go on a tour this summer．
| A．how | B．why | C．when | D．Where |
一Excuse me，sir．This is a non-smoking train．
一Oh，sorry．I____ know that．
| A．haven’t known | B．hadn’t know |
| C．didn’t know | D．don’t know |
Sorry to have kept you waiting so long，but it’ll still be some time____Mr．Smith is available．
| A．when | B．before | C．after | D．Since |
People would like to listen to officials talk____，for no one likes an endless and empty talk．
| A．seriously | B．fluently |
| C．frequently | D．Plainly |