Don't+Look+a+Gift+Horse+in+the+Mouth

[|http://books.google.com/books?id=S1Ze9MdX6w4C&printsec=frontcover&dq=Profiles+in+Folly&hl=en#v=onepage&q&f=false]

1. What is the Trojan Horse?

2. What is Vanity and what role does it play in the story?

3. The is an old saying "never look a gift horse in the mouth" how does that relate to this story?