我们家有四口人，一个是婴儿。

There are four people in our family, and one is a baby.

我们家有四口人，我父母，我哥哥和我。

We have four, my parents, my brother and I.

我们家有四口人，他们是我的爸爸、妈妈、姐姐和我。

There are four people in my family. They are my father, mother, sister and I.