VOA慢速英语:未来的太空旅行会如何造成语言交流问题

isolate – v. separate someone or something from other people or things

concept – n. an idea or principle

emerge – v. appear from somewhere

vocabulary – n. all the words in a particular language

dialect – n. a form of language people speak in a particular part of a country

tone – n. the quality of a sound

occur – v. to happen

manual – n. a book that contains directions for doing something