Immigration naturalization test: what does it mean that the United States is a country ruled by law?

Green cards are for foreigners to immigrate to the United States. Even if you get an American green card, you can live, work and study in the United States, but you have to pay taxes-basically the same rights and obligations as citizens, but you don't have the right to vote. In addition, the green card may be cancelled (for example, an immigration officer can take your green card if he thinks you have no intention to live in the United States), but the "citizen" will not be cancelled. After living in the United States for five years, green card holders can apply for citizenship and take citizenship exams. As long as you are prepared (there are officially published "textbooks"), it won't be too difficult (the purpose of the exam is not to make things difficult for you). The United States recognizes dual citizenship (for example, a Korean can be a citizen of both Korea and the United States and hold passports of both countries), but China does not allow dual citizenship at present. If you want to be naturalized in the United States, you must give up China International.