5. Principles of International Commercial Contracts (PICC) is a A. Convention B. Model law C. Municipal law D. Custom 6. Please describe the Essential elements of a valid contract under common law system. 7. Please describe the Valid Time of Acceptance under different legal systems 8. What is undue influence? And in what relationships does "undue influence" often happens? 9. What is Duress in contract law? 10. What is a legal remedy in contract law?- 11. What are the Buyer's and seller's remedies under CISG? 12. In case Avery v Bowden (1856), a ship was supposed to pick up some cargo at Odessa. With the outbreak of the Crimean War, the government made it illegal to load cargo at an enemy port, so the ship was excused from performing due to A. Impossibility of performance . B. supervening illegality C. frustration of purpose D. commercial impracticability 13. What is a Voyage charterparty? 14. What is a constructive total loss? 15. Please shortly describe the National Monetary Systems