本节只讨论其中的两类: 金属离子钝化剂和过氧化物分解剂.Only two types will be included in present discussion: metal - ion deactivators and peroxide decomposers.为方便起见,材料分为三大类: 金属, 塑料或聚合物和陶瓷.It is convenient to divide materials into three main types...
The silver-leaved varieties of cyclamen are not quite as hardy.银叶仙客来品种不太耐寒。Canned varieties of beans and pulses are a good standby.各种豆类罐头制品是很好的常备食品。Some seed varieties germinate fast, so check every day or so.有一些种子发芽快，所以...