Happiness is a butterfly, which, when pursued, is always just beyond your grasp, but ________, if you will sit down quietly, may alight upon you.
It is the test system, rather than the teachers,_______ is to blame for the students' heavy burden nowadays.
—_____ do you like the match? —More exciting than _____.
Betty’s parents are away for the week, so I think I’d go over to keep her _____.
True friendship is like sound health, _____ value is seldom known until it is lost.
_____ not to hang out at midnight, the boy headed home soon.