1. The law says "All things which are not outside the commerce of men..., may be the object of a contract..." (A) What is meant by "outside the commerce of men"? (B) Give some examples. 2. Contract must have cause. The cause must be lawful. (A) When is a cause in a contract unlawful? (B) Give examples of unlawful causes. 3. In what form must a contract be, to be obligatory? 4. (A) What is meant by "Reformation of Instruments"? (B) When and how does "Reformation of Instrument" happen? 5. (A) What is the primary rule of interpretation in contracts? (B) Give an example. 6. What are: (A) Rescissible contracts? (B) Voidable contracts? (C) Unenforceable contracts? (D) Void or inexistent contracts? 7. (A) What are "Natural Obligations"? (B) Give examples. 8. A owes B P10K. A dies. X, a friend of A's, paid B the P10K indebtedness. B accepted the payment. (A) Was the payment valid? (B) What kind of obligation was this, civil obligation or natural obligation? 9. A found a wallet with P10K, which B lost. (A) Has B the right to recover the wallet and its contents from A? (B) If A returns the wallet to B, can A demand a reward from B for returning it? (C) Give an example of a natural obligation which could happen/ensue, in light of the facts given in this hypothetical case