It’s known to all that the_____ of life is full of hardships.

According to the recent research, heavy coffee drinking and heart attack is not necessarily ______ and effect.

一I’we heard that another brand of milk powder has been banned .－It’s a shame that some companies lack the sense of social responsibility and       ．

-What a pity! He got nothing in ______ for his hard work..

The collapse of the World Trade Center has put US economy in a difficult __________.