单元房里住着一家三代。
中国赡养老人的孩子快不够了，如今一家三代成员的总体情况可以用这样一个“4-2-1”的公式来概括，即四个(外)祖父母、两个父母和一个孩子。
China is running out of children to look after the elderly, a state of affairs often summed up by the formula "4-2-1" : four grandparents, two parents, one child.
善良的科林一家前后三代成为汉斯一生中唯一的亲人。
The good Collin family—three generations of them –became all the family he was ever to have.
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