从山顶上流下的水在山坡上冲蚀出一条沟渠.The running water from the mountain top eroded a gulley along the slope.可冲蚀土壤部分经常从凸出物剥蚀并降落于洼地.Erodible soil fractions are usually dislodged from projections and trapped in depression.河床部分地就是被这种侵蚀作用冲蚀的...
Hamnett does not believe environmental concern is a passing fad.哈姆内特认为对环境的关注不是一时心血来潮。His interest in photography is only a passing fad.他对摄影的兴趣只是一时的爱好罢了.Collecting stamps is a good fad.集邮是一种好的业余消遣....