Playing QQ's "Happy Farm" by planting, watering, fertilizing, spraying, harvesting and selling of virtual vegetables, fruits and flowers, we can find out _____ all the excitement is about.
Not until the teacher explained the importance of getting up early ______ we promise to come early.
—How about the party ______ at Mary’s house? —Wonderful! Everyone had a good time.
This is the best way ______ I have thought of ______ the problem.
Particular attention must be paid ______ welfare, especially in the poor area.
At this time tomorrow ______ over the Atlantic.