用英语解释名词alien civilisation和manned mission用英语解释这两个名词,就是下定义,不要长篇大论的

alien civilisation（外星文明）: the development and history of the alien, such as how they live,when they exist and so on.
manned mission（载人航天任务）:the challenged tasks that bring astronauts to the outer space by spacecrafts to do some researches so human beings can know more about outer space and develop science technology which benefit for mankink.
希望能帮到你，谢谢~

alien civilisation：the society,culture,and way of life in foreign countries
manned mission an expedition made by a human crew in a spacecraft into space