我是我妈妈的第三个孩子，生我时她20岁。

I am my mother's third child, born when she was 20.

youdao

他第三个孩子的妈妈没人知道。

The mother of his third child is not known.

youdao

他第三个孩子的妈妈没人知道。

The mother of his third child is not known.

youdao