The nature of a water molecule means that it engages in a kind of dance with other water molecules, 因此，它仿佛在与别的水分子一起跳舞，

　　briefly pairing and then moving on, like the ever-changing partners in a quadrille, to use Robert Kunzig's nice phrase. 短时间里配成一对，接着又往前移动——用罗伯特·孔齐希的话来说，就像跳方阵舞那样不断地变换舞伴。

　　A glass of water may not appear terribly lively, but every molecule in it is changing partners billions of times a second. 一杯水也许看上去缺少生气，但里面的每个分子都在变换舞伴，每秒要变换几十亿次。

　　That's why water molecules stick together to form bodies like puddles and lakes, 这就是为什么水分子能教合在一起形成水坑和湖泊的原因，

　　but not so tightly that they can't be easily separated as when, for instance, you dive into a pool of them. 但又没有黏合到密不可分的程度。这一点你只要跳进一个水塘就会知道。

　　At any given moment only 15 percent of them are actually touching. 在任何时候，实际上只有15%的水分子是互相接触的。

　　In one sense the bond is very strong, 在一定意义上，这种黏合是非常牢固的，

　　it is why water molecules can flow uphill when siphoned and why water droplets on a car hood show such a singular determination to bead with their partners. 所以，水分子可以通过吸管流往高处，汽车发动机罩上的小水滴会与伙伴们形成水珠。

　　It is also why water has surface tension. 这也是水有表面张力的原因。

　　The molecules at the surface are attracted more powerfully to the like molecules beneath and beside them than to the air molecules above. 表面的分子对于其下面和左右的分子的吸引力要比对于上面空气里的分子的吸引力强大。

　　This creates a sort of membrane strong enough to support insects and skipping stones. 于是，就产生了一层坚固的薄膜，昆虫可以停在上面，你也可以用石子玩打水漂。

　　It is what gives the sting to a belly flop. 它还对跳水起着支托作用。

　　I hardly need point out that we would be lost without it. 我几乎用不着指出，没有水，就没有我们。

　　Deprived of water, the human body rapidly falls apart. 没有了水，人体会迅速散架。

　　Within days, the lips vanish "as if amputated, the gums blacken, 有一篇报道说，不出几天，嘴唇会消失，“像是被割去了似的，齿龈会发黑，

　　the nose withers to half its length, and the skin so contracts around the eyes as to prevent blinking." 鼻子会缩成原先的一半长，眼睛周围的皮肤会缩到无法眨眼睛的程度”