电弧

But financial speculation forced the futures price of some commodities well above the spot level, an unusual phenomenon known as "contango".

但是受投机交易影响，期货价格远高于现货水平，这个就是不常见的期货益价现象。

The mortality of lung cancer and mesothelioma may significantly increase among r esidents exposed to low concentration of crocidolite.

居民在环境中接触低浓度青石棉可引起恶性肿瘤，尤其是肺癌和间皮瘤死亡率的增高。