阅读下列材料，回答问题。

材料在中国历史上，胡适被称为“新文化运动的主将之一、中国自由主义的先驱”。拥有三十二个博士头衔（经袁同礼考证，胡适共获得博士学位36个。）他兴趣广泛，著述丰富，作为学者他在文学、哲学、胡适史学、考据学、教育学、伦理学、红学等诸多领域都有深入的研究。1939年还获得诺贝尔文学奖的提名。

胡适深受赫胥黎与杜威的影响，自称赫胥黎教他怎样怀疑，杜威先生教他怎样思想。因此胡适毕生宣扬自由主义，提倡怀疑主义，并以《新青年》月刊为阵地，宣传民主、科学。毕生倡言“大胆的假设，小心的求证”、“言必有征”的治学方法。

胡适被认为是新红学的开山鼻祖。胡适研究《红楼梦》主要运用的是科学的考证方法。他指出《红楼梦》应当重视史料的收集整理，从作者、作者家世以及《红楼梦》的版本进行研究考证。胡适《红楼梦》研究的成果十分丰富。比如《红楼梦》的作者是曹雪芹、曹雪芹祖父曹寅的情况，曹雪芹写作《红楼梦》的时间大概在乾隆初年到乾隆十三年。

胡适的成果极大地超越了以王雪香、张新之和姚燮为代表的题咏、评点派红学，也超越了以王梦阮、沈瓶庵、蔡元培等为代表的索隐派红学，将红学研究推到了一个前所未有的高度，真正地将其纳入到了科学研究的范畴。

根据材料，指出胡适的思想主张、学术方法和历史地位。

There is a difference between science and technology. Science is a method of answering (1) questions; technology is a method of solving practical problems. Science has to do with discovering the facts and relationships between (2) phenomena in nature and with establishing theories that (3) to organize these facts and relationships; technology has to do with tools, techniques, and (3) for applying the findings of science. Another (5) between science and technology has to do with the progress in each.

Progress in science (6) the human factor. Scientists, who seek to understand the universe and know the truth within the highest degree of (7) and certainty, cannot (8) their own or other people’s likes or dislikes or to popular ideas about the fitness of things. What scientists discover may shock or (9) people-as did Darwin’s theory of evolution. But even an unpleasant truth is (10) than likely to be useful; besides, we have the choice of refusing to believe it! But (11) so with technology; we do not have the choice of refusing to hear the sound produced by a supersonic aircraft flying overhead; we cannot refuse to breathe polluted air. (12) science, progress in technology must be measured (13) the human factor. The purpose of technology is to serve people—people (14) , not merely some people; and future generations, not merely those who presently wish to (15) advantage for themselves.

We are all familiar with the (16) use of technology. Many people blame technology itself (17) widespread pollution, resource depletion (枯竭) and even social decay in general—so much (18) the promise of technology is " (19) " That promise is a cleaner and healthier world. If wise applications of science and technology do not (20) a better world, what else will

18（）

A. in that

B. as if

C. so that

D. if only