It is reported that _______ the young, with their parents working in distant cities, suffer from a sense of loneliness. 

Going to college isn’t the only way out; our society is         people with widely different abilities.

Thank god，you finally returned home ________.You can never imagine how I worried about you when I was told about the terrible accident.

 The Australian boy has a good ________ of Chinese and can express himself freely in it.

A lot of children never fully ______ their mothers until it is too late.