刚果难民学习在美国生活，但要多久？

carpenter – n. one who works making or fixing wooden objects or wooden parts of buildings

efficiency – n. the ability to do something or produce something without wasting materials, time, or energy

translate – v. to explain one language into another language

manager – n. one who controls people and things at an office or store

persecution – n. the practice treating someone badly because of race or religious or political beliefs

ancestry – n. the people who were in your family in past times