For me, scientific knowledge is divided into mathematical sciences, natural sciences or sc

iences dealing with natural world, and sciences dealing with mankind. Apart from these sciences is philosophy. All this is pure or【C1】______ knowledge, sought only for the【C2】______ of understanding in order to fulfill the need to understand what is intrinsic and consubstantial (同质的) to man. What【C3】______ man from animal is that he knows and needs to know. ff man did not know that the world existed, and that the【C4】______ was of a certain kind, that he was in the world and that he himself was of a certain kind, he wouldn't be man. The technical aspects or applications of knowledge are equally necessary for man and are of the greatest importance,【C5】______ they also contribute to【C6】______ him as man and permit him to【C7】______ a life increasingly more truly human.

【C8】______ even while enjoying the results of technical progress,【C9】______ must defend the primacy and autonomy of our knowledge. Knowledge sought【C10】______ for its practical applications will have immediate and 【C11】______ success, but not the kind of important result【C12】______ revolutionary scope is in large part unforeseen, except by the imagination of the Utopians. Let me recall a well-known example, ff the Greek mathematicians had not applied themselves 【C13】______ investigation of conic (二次曲线) sections zealously and without the least suspicion 【C14】______ it might someday be useful, it would not have been possible【C15】______ later to navigate far from shore. The first man to study the nature of electricity could not imagine that their experiments, carried on because of mere【C16】______ curiosity, would eventually lead to modern electrical technology, without which we can scarcely【C17】______ of contemporary life. Pure knowledge is valuable for its own sake, because the human spirit cannot【C18】______ itself to ignorance. But,【C19】______ ,it is the foundation for practical results that would not have been reached if this knowledge had not been sought【C20】______ .

【C1】

A．applicable

B．feasible

C．practical

D．theoretical