(1) "The cattle in the north of the mountain plow the fields and the buffalo in the south of the mountain plow the fields" Inferred from the proverb, this mountain range is the dividing line between paddy fields and dry land in China, so this mountain is the Qinling Mountains in central China;

(2) Among A, B, C and D, B and C belong to temperate monsoon climate and D belongs to subtropical monsoon climate. These three places have both rainy and hot climate characteristics. Only A belongs to temperate continental climate, with hot winter in Leng Xia and scarce precipitation.

(3) Hydrological characteristics of rivers should be analyzed from four aspects: water level, discharge, sediment concentration and ice age. From the position of C and D, the most obvious differences between the two rivers are as follows: the river of C has a long ice age, while the river of D has no ice age;

(4) Characteristics of temperature distribution in China: the temperature difference between north and south is very large in winter and generally higher in summer; The spatial distribution of precipitation gradually decreases from the southeast coast to the northwest inland, so it is inferred that the climate difference between A and B in summer should be precipitation.

So the answer is: (1) Qinling; See figure; ? (2) A; (3) The rivers in Area C have a long glacial period, while the rivers in Area D have no glacial period; (4) precipitation.