When this tensor vanishes, the space is calleda flat.当这一张量为零时,空间叫做平直空间.If the circulation vanishes at one instant of time, it must vanish for all times.只要环量在某一瞬间为零, 它就必须永远为零.With this said, the old man vanishes out of si...

vanishes的音标：...

v.消失( vanish的第三人称单数 )，突然不见，不复存在，绝迹...