a program of rocket-powered flights undertaken by US between 1961 and 1963 with the goal of putting a man in orbit around the earth
双语例句
1
He was the only astronaut who flew in three of the nation's pioneering space programs: Mercury, Gemini and Apollo.
他是唯一一个同时参加过“水星”“双子星”和“阿波罗”先遣计划的宇航员。
2
But the increase of these lighting systems on the market will require more developed recycling programs and increased awareness of the effects of mercury on human health and the environment.