— Remember this: ________ careful you are, ________ mistakes you will make.— We know, Miss Gao.

Rather than ___ on a crowded bus, he always prefers _____ a bicycle.

It was not immediately obvious _____ water was to be fundamental to the development of life.

— Should people stop using their cars and start using public transport?— __________. The roads are too crowded as it is.

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