在冬天,一场大雪过后,人们会感到窗外万籁俱寂。这是怎么回事?难道是人为的活动减少了吗?为什么在雪被人踩过后,大自然又恢复了以前的喧嚣?原来,刚下过的雪是新鲜蓬松的,它的表面层有许多小气孔。当外界的声波传入这些小气孔时便要发生反 In the winter, after a heavy snowfall, people feel the silence of the window. Is this what's going on? Is it a reduction in man-made activities? Why is nature restored to its previous hustle after snow was trampled? Originally, the snow just passed was fresh and fluffy, and its surface layer had many Stomatal. When the outside sound waves into these small pores will have to counter