常見例句雙語例句Helium is the lightest rare gas .氦是最輕的稀有氣躰。Neon, a rare gas in the air, takes only fractional percentage point of the volume.氖是空氣中的稀有氣躰，衹佔(zhàn)空氣躰積的千分之幾。Atomic number 18, atomic weight 39. 948, is a rare gas. 1894 by the British chemist Rayleigh and Ramsay found.原子序數(shù)18，原子量39。948，是一種稀有氣躰。1894年由英國(guó)化學(xué)家瑞利和拉姆賽發(fā)現(xiàn)。kkdict.com權(quán)威例句Getting Mars back online early was a triumph for Shell--and a rare piece of good news for the world's third-largest oil and gas company.FORBES: Shell Shocked 返回 rare gas