If only he________ quietly as the doctor instructed, he would be better now.
-----Tim, please don’t talk in class. -----Pardon? -----I _____ talk in class.
When Jack arrived, he learned Mary _____ for almost an hour.
The speaker mentioned some writers and books _____ were known to us.
-----I called you at about half past eight last night but nobody answered. -----Oh, I _____ in my office at that time.
The number of deaths will be reduced greatly if people _____ to eat more fruits and vegetables.