Read the map of a certain area in China (as shown in figure 1) and answer the following questions with relevant materials. Material 1 According to China Weather Network: 20 13 to 1.2,

(1) As can be seen from the figure 1, ④ Jiangxi Province, ⑤ Anhui Province;

(2) As can be seen from Figure 2, the Jingjiang reach of the Yangtze River is particularly curved. After the founding of New China, a flood diversion project was built in this reach by using low-lying land, and many bending and straightening projects were completed, and the flood control levees were strengthened. The benefits of comprehensive management of Jingjiang reach are beneficial to flood control and shipping development.

(3) According to the third data, the "Middle Triangle" refers to the metropolitan area with Wuhan-Nanchang-Changsha as the core, and the railway trunk lines running through this area include Beijing-Guangzhou Line and Beijing-Kowloon Line.

(4) As can be seen from Figure 1, A is Hainan Island and B is Taiwan Province Island. The favorable conditions for agricultural development in the two islands are as follows: ① the same period of rain and heat; ② The coastal terrain is flat and the soil is fertile; (3) biodiversity; ④ The sea area near the island is vast and rich in fishery resources.

So the answer is: (1) Jiangxi; Anhui; (2) Contribute to flood control; Develop shipping; (3) Beijing-Guangzhou line; Beijing-Kowloon line;

(4)① The rain and heat are in the same period; ② The coastal terrain is flat and the soil is fertile; (3) biodiversity; ④ The sea area near the island is vast and rich in fishery resources.