题目

Stephen Hawking, a world famous British physicist, died on March 14, 2018. Many people around the world felt so sad about his death. Hawking once wrote a children’s book with his daughter when he was alive. Hawking said the book would be a bit like Harry Potter but without the magic. It explains the wonders of the universe(宇宙), said Hawking, while he was on a visit to Hong Kong.Hawking is probably the world’s most famous scientist after Albert Einstein. He is an expert on black holes. He has put his whole life into digging into the beginning (and the end) of the universe.My goal is sim空气里含有下列成分，其中都不属于污染物的一组是 （ ）A. 氮气、氮氧化物 B. 氧气，二氧化硫C. 碳粉尘，二氧化碳 D. 水蒸气，氧气 D 【解析】A、氮气是空气中的成分之一，不是污染物，氮的氧化物如二氧化氮等溶于水形成酸雨，是污染物，错误； B、氧气不是污染物，二氧化硫溶于水形成酸雨，是污染物，错误； C、碳粉尘是悬浮于空气中的固体污染物，二氧化碳不是污染物，错误； D、水蒸气和氧气都不会对空气造成污染，正确。故选D。