一、选择题(50分) 以下各题的选项中,只有一项最符合题意,请将正确选项的序号在答题卡上涂黑。(每小题2分,共50分) 家住南京的小欣发现伏早时,南京的天空格外蓝,气温特别高,但有时出现第二天气温较前一天低5℃以上的情况,据此判断1一2题: 1.此时段南京的天空格外蓝的原因是 ① First, multiple-choice questions (50 points) Among the options for each of the following questions, there is only one item that best matches the question. Please mark the correct option number on the answer sheet. (2 points for each question, a total of 50 points) Xiaoxin, who lives in Nanjing, discovered that in early days, the sky in Nanjing was particularly blue, and the temperature was particularly high. However, sometimes the temperature of the second day was lower by 5°C or more than the previous day. Judgment 1 to 2 questions: 1. The reason why Nanjing’s sky is particularly blue during this period is 1