A thrombus has formed in his vena cava.

The umbilical vein plays a crucial role in transporting nutrients and oxygen to the fetus.

The baby's umbilical vein plays a crucial role in transporting nutrients from the mother.

My father underwent surgery for varicose veins.

He is not that sort of person.

This is the kind of book I like.

He is not that kind of person.

Mr. To-in is my best friend.

The olm is a very rare creature that lives in caves.

He is good at playing the xiao.