What Makes a Twin?

是什么造就了双胞胎？

Usually , human mothers only have one baby at a time.But sometimes two babies are born together-twins.

通常，人类母亲一次只能生一个孩子。但有时两个婴儿出生在一起-双胞胎。

There are two kinds of twins:identical and fraternal. They get to be twins in different ways.

有两种双胞胎：同卵双胞胎和异卵双胞胎。他们以不同的方式成为双胞胎。

Sometimes two eggs get fertilized separately and grow into babies at the same time.This results in fraternal twins.

Fraternal

means "brotherly"

有时两个卵子分别受精，同时发育为婴儿。这导致了异卵双胞胎。

Fraternal

的意思是“兄弟”。

Fraternal twins are just like normal brothers or sisters, except that they are born together instead of a couple of yeas apart.Fraternal twins each have different DNA.Because they develop from two separate eggs.Fraternal twins don't look any more alike than normal brothers and sisters-and one can be a boy and one a girl

异卵双胞胎就像普通的兄弟姐妹一样，只不过他们出生在一起，而不是相隔几年。异卵双胞胎都有不同的DNA，因为它们是从两个分离的卵子发育而来。异卵双胞胎和正常的兄弟姐妹长得不一样，其中一个可以是男孩，另一个可以是女孩.