________by the advances in technology, many farmers have set up wind farms on their land.
Walmart,which is one of the largest American supermarket chains,________ some of its stores open 24 hours on Mondays through Saturdays.(2012·安徽)
—Goodbye,John.Come back again sometime.—Sure,________.
It's the first time that he has been to Australia,________?
You and I could hardly work together,________?
He must be helping the old man to water the flowers,________?