(adj.) requiring or apparently requiring no effort; 'the swallows glided in an effortless way through the busy air' .
校对:卢埃林
双语例句
The miracle of a bird's flight, that st eady and almost effortless motion, had interested Langley intensely--as had also the sun's radiation--from the years of his childhood. 李贝.西洋科学史.