It is strange that he ______ (leave) without a word. It is not like him.
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—When ______ this kind of computer ______ —Last year. (design)
If there ______ (be) no air, people would die.
The teacher told us that tomorrow December 25 ______ (be) Christmas Day.
The average lifespan for these men ______ (should be) 68 years, if they’d aged twice as fast during their years in office as the popular wisdom suggests they do.