we didn't expect to have salmon, in some cases, changing the vertical position of a river channel up to 30 percent more than it would have without salmon in it. 这句话是翻译成:我们没有想过有鲑鱼,河道的垂直距离会比没有鲑鱼多改变30%左右。 还是翻译成:与没有鲑鱼的河道相比,我们没有想过鲑鱼会将河道的垂直距离改变30%左右。
这里in some cases是插入语,给出额外的信息“在一些情形下”(而不是全部!)。up to...在这里的意思是“多达...”。由于than后面用的是虚拟语气,所以up to 30 percent more than it would have without salmon in it=If there hadn't been salmon there, it would have been up to 30 percent less changes than it was right now. 整句译文:我们没有想到会有鲑鱼。在一些情形下,与没有鲑鱼的河道相比,这些家伙(鲑鱼)将河道的垂直距离改变了多达30%。
we didn't expect to have salmon, in some cases, changing the vertical position of a river channel up to 30 percent more than it would have without salmon in it. 我们没想到会有鲑鱼,在某些情况下,改变河道的垂直位置,比没有鲑鱼的地方增加30%。 如果有帮到你,请采纳,还需帮助,请继续问。