near in blood
A:Cross-cousin marriage is not allowed in China.
A:姑表兄妹在中国是不允许通婚的。B:It is true of many countries.
B：其他许多国家也是这样。
A:You know why?
A:你知道为什么吗?B:Sure. If people are near in blood, they might pass on some genetic diseases to the next generation.
B：当然，近亲结婚会带给下一代某些遗传疾病的。