I have worked with children before, so I know what ______ in my new job.
_____ three influenza type A virus subtypes(子类型) have been found in pigs.
Who would you rather ______ you repair your CD player?
We decided to take a taxi.Luckily there was _____ waiting.
Ted has made up his mind to give it up, but on _____ second thoughts he determined to try______ third time.
—Aren’t you cold? —____.I’m boiling.