近日,听到一则“关上窗帘”的故事:据说美国华盛顿广场有名的杰弗逊大厦,因年深日久,墙面出现裂纹。为了保护这座大厦,有关专家进行了专门研讨。最初大家认为损坏建筑物表面的元凶是酸雨。而进一步研究,却发现对墙体侵蚀最直接的原因,是每天冲洗墙壁所用的清洁剂对建筑物的酸蚀作用。为什么每天要冲洗墙壁呢?是因为墙壁上每天都有大量的鸟粪。为什么会有大量的鸟粪呢?因为大厦周围 Recently, I heard a story of “Closing the Curtains”: It is said that the famous Jefferson Tower at Washington Square in the United States has been cracked in the walls for years. In order to protect the building, the experts conducted a special seminar. At first, everyone thought that the culprit that damaged the building surface was acid rain. However, further research has found that the most direct reason for the erosion of the wall is the acid etching action of the cleaning agent used to flush the wall every day. Why wash the walls every day? Because the wall every day a lot of guano. Why there is a lot of bird feces? Because around the building