Stealing salt was considered a major crime during some eras of history.在某些历史时期,曾把偷盐定为大罪.Usually , historical eras are defined by accomplishments analyzed with the benefit of contextua 1 hindsight.如何定义具有重在历史意义的时代呢?这取于这时代中...
Once its impurities had settled, the oil could be graded.一旦杂质沉淀下去，油就可以分级了。Passes are graded from "A" down to "E".及格分为A到E几等。The texts should be graded in order of difficulty.课文要按难易程度编排....