许多到过北海的朋友,都说北海是一座天然的“大氧吧”。北海由于三面环海,加上传统原始工业总量小的缘故,城市空气中负离子的含量高出内地城市50甚至100倍。江苏省有一对夫妇,为了配合儿子治疗呼吸道方面的疾病,特地移居北海,借清新的空气与没有严寒和酷暑的气候来辅以治疗。东北和西北各省市的许多退休 Many friends who have been to the North Sea say that the North Sea is a natural “big oxygen bar.” Due to the three seas encircling the sea and the small total amount of traditional primary industry, the North Sea has a negative ion content of 50 or 100 times higher than that of the mainland cities. In Jiangsu Province, there are a couple who, in order to cooperate with their son in the treatment of respiratory diseases, have specially relocated to the North Sea to supplement the treatment with fresh air and a climate without severe cold and heat. Many retirements in Northeast and Northwest provinces