If your old friends or family members are over 80 years old, you can refer to the following website of American Visa official website to help them get an American visa:
ustraveldocs.com/cn_zh/cn-niv-visarenew.asp
In addition to age, the website also lists other conditions that need to be met. Although there will be no problem under normal circumstances, to be on the safe side, please check carefully one by one before submitting your application to ensure that nothing is wrong.
I wish you a successful application! Remember to adopt satisfactory answers ~? :-)