2. It nearly always slips away from one like sand through the fingers, like water through a
leaky pail.

它几乎总会从你身边溜走,就如沙粒从指间滑落,或像水从漏桶流失一样。
3. A mathematical model for groundwater pollution in a
leaky aquifer system, which involves the adsorption of semipervious layer, is presented.

提出了一个越流含水层系统考虑弱透水层吸附作用的地下水污染数学模型。