What materials do parents need to visit relatives in the United States?

You need to prove and convince the visa officer that your parents have no tendency to emigrate and will definitely return to China on time. The following materials need to be prepared:

1. Prove your relationship with your parents (for example, prepare some photos you took with your parents).

2. Prove that your parents will return to China (for example, your parents and boyfriend/girlfriend are both in China, your parents have a house in China, and your parents are capable of finding a good job in China, etc.). )

3. The approximate itinerary of your parents in the United States (such as where they will travel, the approximate timetable, so that visa officers will tend to believe that you are really traveling, and it is hard to believe that a person who spends so much money to go to such a far place has no itinerary)

4. proof of funds (proof that you have enough money to travel to the United States)

As for whether you can sign it, it depends on whether your materials are well prepared, and whether you performed well at that time depends on luck. Good luck.