The mechanics work hard to keep the he-licopters airworthy.机修工努力维持直升机的飞行性能。Both quantum mechanics and chaos theory suggest a world constantly in flux.量子力学和混沌理论都表明世界永远处于不断变化中。What are the mechanics of this new process?这一新...
Mars has an insubstantial atmosphere, consisting almost entirely of carbon dioxide...火星的大气层极其稀薄,几乎全部由二氧化碳构成。Gasfired heaters should not be used in corrosive or explosive atmosphere.燃烧煤气的加热器不宜用于有腐蚀性或危险性的气体中.As the lungs e...