By the time Jack returned home from America, his son __________ from college.
—Are you satisfied with what he did? —No. It couldn’t have been _____.
This year __________ to be another good one for harvests.
Perhaps it is true that nobody in the world knows exactly how the earth __________.
—Why don’t we choose that road to save time? —The bridge to it __________.
Don’t be so upset. It won’t be ___________ your children can return to school again.