读下图中国1月平均气温分布示意图，结合所学完成下列要求：

（1）图中AB是我国1月____ ℃等温线。该线以北地区1月平均气温在____ ℃以下，该线以南地区1月平均气温在____ ℃以上；该线大致通过的地区是青藏高原东缘和____ ——____ 一线。
（2）从图中可以看出，漠河比海口纬度____ ，漠河离影响我国的冬季风发源地 ____ ，漠河比海口1月的平均气温____ ；海口与漠河1月平均气温相差在____ ℃以上。
（3）我国1月平均气温分布有什么特点____ 

An Englishman was showing a foreign visitor around London. "What's that strange building?" asked the visitor. "That's the Tower of London." "I see. How long did it take to build it?" "About 500 years." "In my country we can build it in five months." said the visitor. A short time after that, they come to St. Paul's Cathedral (大教堂)."Very interesting, "said the visitor, "How long did it take to build it?  Nearly forty years." said the Englishman. "In my country we can finish it in forty days." said the visitor. This went on all day. They visited most of the best known buildings in the city. Every time they saw a new one, the visitor asked what it was and how long it took to build it. Then he said that they could do the same things much faster in his country. At last the Englishman got angry with the visitor though he tried not to show it. A few days later they came to the House of Parliament(议会大厦) and the visitor asked his usual question. "What's that?" The Englishman answered, "I've no idea. It wasn't there last night."

已知函数f（x）=2sin²x+sinx•cosx+cos²x，x∈R． 求：

（1）f（$\frac{\mathrm{\pi }}{12}$）的值；

（2）函数f（x）的最小值及相应x值；

（3）函数f（x）的递增区间．