All the scientific evidence ________ that increasing use of chemicals in farming ________ damaging our health.(2012·湖南)
| A．show；are | B．shows；are |
| C．show；is | D．shows；is |
Walmart，which is one of the largest American supermarket chains，________ some of its stores open 24 hours on Mondays through Saturdays.(2012·安徽)
| A．keeps | B．keep | C．have kept | D．had kept |
—Goodbye，John.Come back again sometime.
—Sure，________.
| A．I did | B．I do | C．I shall | D．I will |
It's the first time that he has been to Australia，________？
| A．isn't he | B．hasn't he | C．isn't it | D．hasn't it |
You and I could hardly work together，________？
| A．could you | B．couldnt' I |
| C．couldn't we | D．could we |