参考答案1 Approximately 2 erosion 3 importance 4 contains 5 puzzled 6 economy 7 balance 8 remove
参考答案1 approximately 2 crops 3 erosion 4 puzzled 5 view6 contain 7 soil 8 remove
HEADLINE HERESubtopicsdetailsThe UNIVERSITY of NORTH CAROLINA at CHAPEL HILL Fluid Dynamics with ErosionBrandon LloyP 259May 2003Overview Sediment transport in open channelsBed-load transportSuspe