Strongly recommended:modify the policy of join nationality in USA Part1

detailed:
1 must have permanent resident status (include temporary resident status in previous) enough 4 years, and has lived in the country accumulative enough 3 years.
2 The person's oral proficiency (one of the conuntry's official language or main common language) must be favorable.The ability of read and write the national language (one of the conuntry's official language or main common language) must be qualified.
3 Must have college diploma (2 or 3 years of school system) or higher.(Except the specialty of literature,history,philosophy or some humanities)
4 Have enough work experience in the country.
5 At least in most recent six months,must have stable work and enough income.
6 Must have continuous, stable and enough income in USA