有个老师的回复是这样的
Right now, unfortunately, all of my funded RA spots are full. I have a proposal under review that would support another student, but that funding decision will not be known for a few months. Therefore, for now, the additional students I can safely say I could incorporate into my research group are those with a separate source of funding, such as a fellowship (NSF, NASA, etc.). If you were to obtain a fellowship, you might be the type of student that would fit in well in my group.