通读短文，根据短文内容，在窄格处填入一个使短文内容完整、正确的单词。

Every year, many young people in the country of western China go to the big cities to work. Most of them come __78__ once a year. Some even don't come home for a few years. Their children stay at home and live with their grandparents. These children can't see their __79__ for a long time. They are called left-behind children(留守儿童).

Wang Yuan, a child left at home, is a hard-working child. His parents have __80__ to Shenzhen to work. He hasn't seen them for two years. He often feels __81__. He says, "I miss my mum and dad very much, but I know what they've done is for the family. I must try my best to look __82__ my grandparents at home." He studies hard at school and does __83__ in all the subjects. When he comes home after school, he always does many chores for his grandparents. He is only ten years old, __84__ he can do many things like an adult (成年人) now.

It's reported that there are 83 million left-behind children in China. We must __85__ about their life and study. Although their parents are not at home, we can still try to cheer them up. If we do this well, they won't feel lonely any more. This is our duty.