You don't need a guarantee, just show the admission notice of the scholarship (TA or RA) given to you by the department.

After winning the full prize, property security is basically not important. I didn't do it.

Of course, I heard that some people were rejected, but rarely.

But you are only preparing your application now. This problem will be considered next year. I suggest you do something.

Because the visa form in the United States is excellent, but it has been unstable, so it is better to be safe.

My major is cultural anthropology. Who is your tutor? Which school? Don't be acquaintances.