Can the financial guarantor who applies for a green card in the United States be a husband and wife?

American relative immigration guarantee? Requirements of

1, guaranteed? Should it be a relative of the immigrant applicant, an American citizen living in the United States (including territory and possessions) or a green card holder? Age? A teenager must be 18 years old. ;

2. American citizens or green card holders? As a financial guarantee for relatives? When, promise? Is economic security okay? Must meet the federal poverty line standard125% published by the US Immigration Service;

3. guarantee? Do you need to include guarantees when calculating their families? Ben. , and family members living under protection, rely on protection? Support? What about all the immigration applications?