更为明确，就是赖着不走的非法入境者（外籍）。不要叫非法移民（illegal
immigrants）了，省得总被spin成把已成为公民的也包含在内。
The words alien and immigrant are not exactly interchangeable, but “
immigrant” is perceived as having a more positive connotation than ”alien.”
An immigrant is a person who moves from one country to settle in another.
An immigrant may or may not be a citizen. An alien is definitely not a
citizen.
