Being examined twice a year, whether it is a car or a bus or a truck, is the rule that every driver _____ obey in this city.
It is ____ waste of time for young men to devote themselves to playing computer games on ___ Internet only for _____ pleasure.
---What’s the chief ______ of the world this year? ---I think the Twin- Tower was destroyed.
___________ a fine day, Shenzhou VI will be launched on time according to its planned time.
— Excuse me! — _____ — How can I get to the nearest post office?
Be careful with such things. If you _____, you’ll drop them.