( 1).b、d

(2). From southeast to northwest 80

(3) The area where the B-B reach is located has a wide catchment area, large discharge, flat terrain and balanced water flow.

(4) Located in the river valley, the terrain is flat, the soil is fertile, and the urban living materials are adequately supplied; The city is built along the river and has abundant water resources. Located at the intersection of rivers, it has a large flow of people and materials and convenient transportation; Located in North China, it belongs to a warm temperate zone with a suitable climate; Preferential policies of the government; Rock climbing tourism has promoted the development of the city.

(5) The rock wall near the city is steep and upright, with high suitability; The rock wall is located in an open area, which can accommodate more tourists; Climbing wall is close to the city and has a broad market; Strong government support and perfect security measures.

?

(1) Determine the valley according to the curvature of the contour line, and there may be rivers in the valley.

(2) To judge the flow direction of the river, we should pay attention to the navigation marks in the picture; According to the formula (n- 1) d ≤ h < (n+ 1) d, the relative height of the cliff is between 40 and 80 meters.

(3) Navigation conditions are closely related to river flow, topography and other factors, and navigation conditions are better in river sections with flat terrain and large flow.

(4) City C is located at the intersection of two rivers, and its development is related to water resources, climate, transportation, tourism and other factors.

(5) The development of rock climbing needs suitable terrain conditions, markets, preventive measures and policy support.