He said he would come to attend the lecture if he ___________ time.
— When did you first meet Tom?— On May 2, ____, the first day I came to this city.
. The millions of calculations involved, had they been done by hand, _____ all practical value by the time they were finished.
_____ what he can do. He might get a job tomorrow. He might stay out of work for weeks.
Students shouldn’t be given so difficult a problem_________they cannot work out.
Everyone likes_________of the two stories, for this story is _________than that one.