Some young men don't try their best ti make themselves valuable to the human beings.

Some young men don't try their best ti make themselves valuable to the human beings.

一些年青人不努力使自己成为一个对人类有用的人.

一些年轻人没有尽全力去做一个有用的人。

许多年轻人不尽力去使他们对人类（社会）更有价值。