Read the map of "Four Geographical Regions of China" and answer the following questions: (1) The area where Lianyungang is located _ _ _ (fill in the letter code). (2) Divide the boundary ①.

(1) Lianyungang, called "Haizhou" in ancient times, is named Lianyungang because it faces Liandao and is backed by Yuntai Mountain. Located in the eastern monsoon region north of Qinling-Huaihe River in China, it belongs to the northern region.

(2) ① The annual precipitation line of 400 mm roughly divides China into southeast and northwest. The southeast half is affected by the monsoon, with abundant precipitation and the same period of rain and heat. The northwest half is located inland, and most areas are seriously short of water or have poor coordination of water and heat resources, which is an important animal husbandry area in China.

(3) "Riding a princess and laughing in the world of mortals, no one knows it is litchi", and the poem "Riding in the South" is a traditional mode of transportation in northern China, and litchi is one of the important fruits in southern China.

So, the answer is: (1) a; (2) precipitation; (3) a; B.