Good landlord, I think we can focus on the analysis from the level of transaction risk. Because trade terms involve a problem of risk division, risk division is divided into FOB, CFR, CIF and so on. Is different, so there are different security considerations between remittance, collection and letter of credit. There are no trade terms in the earliest international trade, so its settlement method is also the simplest, often cash on delivery. Later, due to the continuous enrichment of delivery methods, both parties to the transaction gradually pay attention to the possible risks in the transaction process, and the continuous supplement of settlement methods is also for the same purpose of preventing risks.

One-sided for reference only. I hope your paper goes well.