本案例中为何要实地调查河流的流向:①地势起伏很小 ② 河流密集 ③ 湖泊众多 ④ 地下管线多 ⑤ 河流季节流向变化 ⑥ 辫状水系Why is it necessary to investigate the flow direction of the river in this case?①small terrain undulations ② many rivers ③many lakes ④ma
单选题
本案例中为何要实地调查河流的流向:①地势起伏很小 ② 河流密集 ③ 湖泊众多 ④ 地下管线多 ⑤ 河流季节流向变化 ⑥ 辫状水系Why is it necessary to investigate the flow direction of the river in this case?①small terrain undulations ② many rivers ③many lakes ④ma