gravity

/ˈgrævəti/

1. n. 重力；地心引力；嚴重性

   • In orbit, astronauts float as if they had no weight, so their muscles weaken from not having to work against gravity. 在軌道上，太空人像沒有重量一樣飄浮，肌肉因為不必對抗重力而變弱。