If a person loses wealth,        he loses much.If a person loses friends,        he loses more.If a person loses courage,        he loses all.A person who loses wealth             loses much.
loses friends,more.
loses courage,all.

A person (who loses wealth)              loses much; A person (who loses friends)              loses more;A person (who loses courage)              loses all.
主句、从句、先行词、关系代词

关系代词：
A person who loses wealth loses much; A person who loses friends loses more; A person  ...