______ your teacher the problem with learning, theoretically, and they will help you.

__ won’t be of much help. 

There is no _________ that the Chinese people will present to the world a successful, splendid and unforgettable exposition（博览会）.

The crowd cheered wildly at the sight of Liu Xiang,who was reported _______ the world record in the 110-meter hurdle race.

—Must I turn off the gas after cooking? —Of course, you can never be ____careful with that．