Dear arnold, I don't know if my ancestral lineage is Chinese. From time immemorial, Koreans interacted with Chinese, Manchus, Mongolians, and Japanese. So, mixed blood and cohabitation between them and Koreans frequently occurred.
I am amazed that Americans know about their ancestors well.

The reason Vietnamese people like Koreans and Japanese people is that they have long grudges with Chinese people.
China colonized Vietnam for 1000 years.