请帮忙做一个用英文介绍国际合同法的PPT，万分感谢

Contract law regulates the exchange of promises between parties to perform or refrain from performing an act enforceable in a court of law. Contracts can be formed from oral or written agreements. The concept of a "contract" is based on the Latin phrase pacta sunt servanda (agreements must be kept).[27] In common law jurisdictions, three key elements to the creation of a contract are necessary: offer and acceptance, consideration and the intention to create legal relations. In Carlill v. Carbolic Smoke Ball Company a medical firm advertised that its new wonder drug, the smokeball, would cure people's flu, and if it did not, the buyers would get ￡100. Many people sued for their ￡100 when the drug did not work. Fearing bankruptcy, Carbolic argued the advert was not to be taken as a serious, legally binding offer. It was an invitation to treat, mere puff, a gimmick. But the court of appeal held that to a reasonable man Carbolic had made a serious offer. People had given g