【单选题】氧气是种无色无味无毒的气体,分子式为02,比空气重,氧气本身不能燃烧,但他是一种( )气体。
【单选题】I disagree with the _______ that economic development has priority over the environment.
【单选题】1839年摄影术诞生,被誉为“摄影之父”的是谁?
【单选题】I disagree with the_____ that economic development has priority over the environment.