twice a year, whether it is a car or a bus or a truck, is the rule that every driver must obey in this city.
The question is very important. It really needs _______.
Follow the directions on the bottle carefully when _______.
Do you think ______ important _______ us to learn a foreign language?
-----I think it _______ to smoke . ----- _______.
______ to collage this year, We must study harder than ever before .