Decide whether the following contracts are governed by the CISG 1980? Explain your reason?

1.On 10 January, 2021, a seller with place of business in Hanoi, Vietnam signed a contract to sell medical face masks to a buyer with place of business in Wuhan, China. The parties did not specify the applicable law for their contract at time of conclusion.

2.On 20 November, 2018, a trader based in New Delhi, India signed a contract toexportcotton fabricto a trader based in Berlin, Germany. The choice of law clause in their contract says that: "This contract shall be governed by the laws of Germany".

3.On 8 March, 2020, a company based in Ho Chi Minh City, Vietnam signed a contract with a textilecompany based in Seoul, South Korea under which the Vietnamese companyshall produce dress shirts in accordance with the design by the South Korean company. All materials are to be supplied by the South Korean company. The contract is silent on governing law.