How many elements are there in the formation of a contract, and what are they (choose all that apply)?

For a contract to be valid, the parties must have _____.

A contract can be cancelled if it has been induced by _____ (choose all that apply).

What rule covers third parties rights under a contract?

If I offer a reward to anyone who finds my lost dog, this is a _____ contract.

When you rent a car, you are responsible for the cost of the fuel. This is not in the rental contract, because it is _____.