When you lie down on it, the surface of the mattress under you sinks , forcing the water into other parts of the mattress.
当躺在上面，你身体下面的床垫就会下陷，这就会迫使水流到床垫的其他地方。Though Morgan had a large sense of public duty, he had not shouldered the falling church out of pure altruism.
尽管摩根深感公众责任之重大，但他肩扛下陷教堂之壮举，并非完全源于利他主义。It was near that old and sunken grave, yet with a space between, as if the dust of the two sleepers had no right to mingle.
这座新坟靠近那座下陷的老坟，但中间留着一处空地，仿佛两位长眠者的骨殖无权相混。The Xinhua news agency reported that the early morning quake had caused some schools and part of a government office building to cave in.
据新华社报道，发生在早晨的地震造成学校和一座政府办公大楼下陷。They went out of the store and across the worn gallery and down the sagging steps .
他们走出店铺，穿过破旧的走廊，步下下陷的台阶。Check this out: it went into a sinkhole in Oklahoma. That's a truck.
关注一下这个：一辆卡车在俄克拉荷马州掉进了一个下陷的洞。Environmental pollution is one of the concomitant problems of growth. Shown here is subsidence caused in Pingtung by seaside aquaculture.
环境污染是成长太快，带来的问题之一，图为在屏东沿海养殖，造成地层下陷，而遭取缔的业者。A famous analogy is that of a bowling ball sitting on a trampoline, which creates a dip that a nearby marble will roll into.
这里有一个著名的例子，一个保龄球放在弹簧床上，如果在床上扔一块大理石，大理石会是床产生下陷，于是球会滚进去。They are meant to be used decades from now, perhaps in the next century, when in their old age the concrete girders will start to sag.
这些固定墩打算要从现在开始被使用几十年，或许用到下个世纪。到那时，当混凝土大梁破旧的时候，他们将由于重力或压力而从中间开始下陷。