C 宇航员；航天员 person whose job involves travelling and working in a spacecraft
句型例句
In 1969, astronauts first landed on the moon. 1969年，宇航员首次登上了月球。 The astronauts trained for years in how to use their spacecraft.宇航员们要接受多年的训练，学会如何使用宇宙飞船。 Armstrong was the first astronaut to land on the moon.阿姆斯特朗是第一位登上月球的人。