Some farmers have _____________ keeping deer, and there are now about 4,500 deer farms in the country.
Everyone _____ do his best for the modernizations of our country.
31. He _____ have come here yesterday, but he didn’t.
He ought to win the first prize, _____ he?
I missed the last bus, so I _____ go home on foot.
I got up early that morning, but I _____ so because I had no work to do.