题目

Earlier this week, I wrapped up(圆满完成) a 5-day trip in San Francisco. I woke up a few hours before sunrise, drove through the darkness and out of the city, hiked for 30 minutes to the top of a hill overlooking the Golden Gate Bridge, and snapped(拍摄)this photo. As I stood there soaking in the early morning light, I was reminded of an important lesson. When I arrived in San Francisco, I told myself, Just take photos as you do other things. My primary goal was to meet with friends and so I figured I could take pictures as we walked around the city. This resulted in exactly zero 空气是一种宝贵的资源。请回答下列问题: (1)唐代诗人李峤有一首绝句:“解落三秋叶,能开二月花。过江千尺浪,入竹万竿斜”。诗中揭示的自然现象是　　　　,证明了　　　　的存在。 (2)如图分别表示某些气体的主要用途,这些气体依次是　　　　　　　　　。 (3)洁净的空气对于人类非常重要。下列做法有利于保护大气的是　　　　(填序号)。 A.使用清洁能源　　　　　        B.燃放烟花爆竹 C.大量植树                          D.推广私家汽车出行