Floyd, an African-American man, cried out in pain, "I can't breathe" when he was "kneeled and killed" by a white police officer last year. This is also a microcosm of the real life of some ethnic minorities in the United States. The discrimination, oppression and persecution of ethnic minorities are reflected in all aspects of social life, and the "cancer of racism" has penetrated deep into the bone marrow of the United States.