They swore their allegiance to the U.S. and received their naturalization papers.
他们宣誓忠诚于美国，随后收到了批准他们入籍的文件。
《柯林斯英汉双解大词典》
2
The Constitutional principles that Washington alone has the power to "establish a uniform Rule of Naturalization" and that federal laws precede state laws are noncontroversial.
只有华盛顿有权“建立统一的归化规则”和联邦法律先于州法律的宪法原则是没有争议的。
3
The Immigration and Naturalization Service lacks the resources, and apparently the inclination, to keep track of the estimated 2 million foreigners who have intentionally overstayed their welcome.