Oxygen is often used as reactant in chemical processes.在化学过程中,氧气经常充当为反应物.The synthesis and application of reactant polyurethane fixing agent were introduced.介绍了反应性聚氨酯预聚树脂固色剂的合成及其应用.The influence of reacting temperature a...
太空望远镜拍摄到了迄今为止最清晰的冥王星的照片。The space telescope has taken the clearest pictures ever of Pluto.天文学家知道冥王星与海卫一拥有几乎相同的体积、质量与密度。Astronomers know that Pluto and Triton have nearly the same size, mass, and density.冥王星似乎受到过严重撞击，倾斜了1...