Can American citizens get green cards for adopted adult children?

According to American immigration law, there are four main situations to apply for child immigration:

(1)2 1 Unmarried children of American citizens under the age of can apply for immigration, and there is no quota limit;

(2) Children who have reached the age of 2 1 year, but are unmarried, belong to the first priority category;

(3) Children who are married belong to the third priority category;

(4) Green card holders can also apply for immigration for their unmarried children. Beneficiaries belong to the second priority category, and divorced children are considered unmarried. Married children of green card holders have no priority.