A：Crossed cousin marriage is not allowed in China.
表兄妹在中国是不允许结婚的。
B：It it true of many countries.
其他国家也是这样。
A：You know why?
你知道为什么吗?
B：Sure. If people are near in blood, they might pass on some genetic disease to the next generation.
当然知道，近亲结婚会给下一代带来某些遗传疾病。