精选优质文档-倾情为你奉上完形填空（一）Chemistry did not emerge as a science until after the scientific revolution in the seventeenth century and then only rather slowly and laboriously. But chemical knowledge is as _16_ as history, being almost entirely concerned with the practical arts of living. Cooking is essentially a chemical process; so is the _17_ of metals and the administration of drugs and poisons. This basic chemical knowledge, which was applied in most cases as a rule of thumb, was nev
