今天刚做了这套题。正准备请教高人。怎么觉得都应该是C。cccccco, boundaries可以prevent its acoustic energy from dissipating。 道理跟全反射相似,因为这些反射界面的存在,声音才可能向初始方向传播,从而传播很长的距离。所以说E显然不对,声音不可能prevent its energy from dissipating.主动的应用也导致了by boundaries没有意义。
Sound can travel through water for enormous distances, prevented from dissipating its acoustic energy by boundaries in the ocean created by water layers of differing temperatures and densities.