单选题 《复合题被拆开情况》 Why does the idea of progress loom so large in the modern world? Surely because progress of a particular kind is actually【C1】________place around us and is becoming【C2】________manifest. 【C3】________mankind has undergone no general improvement in intelligence or morality, it has made【C4】________progress in the accumulation of knowledge. Knowledge began【C5】________as soon as the thoughts of one individual could be communicated【C6】________ another by【C7】________of speech. 【C8】________the invention of writing, a great advance was made, for knowledge could then be not only communicated but also【C9】________ Libraries made education【C10】________, and education in its turn added 【C11】________libraries: the growth of knowledge followed a kind of compound interest law, 【C12】________was greatly enhanced by the invention of【C13】________All this was comparatively slow until, with the coming of science, the tempo (速率) was suddenly【C14】________ Then knowledge began to be accumulated according to a systematic plan. The trickle became a stream; the stream has now【C15】________a torrent. Moreover,【C16】________soon as new knowledge is acquired, it is now turned【C17】________practical account. What is called modern civilization is not the result of a【C18】________development of all men’s nature, 【C19】________of accumulated knowledge applied【C20】________practical life.《问题》：【C15】