But, whereas metal prices have fallen, oil prices are reaching record highs. The reason is simple: metal usage has been substituted by many alternatives, but most still require petroleum products as inputs, and decades-long efforts to develop sufficient alternative energy sources have yielded little success.
但是，在金属价格下跌的同时，油价却正创造着历史新高。原因很简单：金属的使用被许多其它材料代替了，但这些材料却大都需要以石化产品为原料。而且我们在开发足够代替能源方面的数十年努力成效甚微。