肝脏是一个内部器官，有助于消化。

The liver is an internal ___organ that helps with digestion.

他决定成为器官捐献者来帮助他人。

He decided to become an ___organ donor to help others.

现代医学允许替换人体中受损的器官。

Modern medicine allows the replacement of damaged ___organs in the human body.