题目

如图所示,在双缝干涉实验中，若把单缝S从双缝S1、S2的中心对称轴位置稍微向上移动，则（ ） A．不再产生干涉条纹 B．仍可产生干涉条纹,其中央亮条纹的位置不变 C．仍可产生干涉条纹,其中央亮条纹的位置略上移 D．仍可产生干涉条纹,其中央亮条纹的位置略下移 答案： D  （3分）19．Since the pre-historic times，man has had an urge to satisfy his needs．Be it hunger，shelter or search for a mate，he has always controlled the situations to his advantage．Probably this might be the reason why we humans are the most developed of all living species on the earth．As we climbed the steps of development，we somehow left behind common sense and logical thinking--we forgot that we have stopped thinking ahead of time．If you are hungry，what do you do？Get a piece of your favorite meal and stay quiet．Just like your stomach，even your mind is hungry．But it never lets you know，because you keep it busy thinking about your dream lover，favorite star and many such things．So it silently began to care about your needs and never let itself grow．When mind looses its freedom to grow，creativity gets a full stop．This might be the reason why we all sometimes think"What happens next？"，"Why can't I think？""Why am I always given the difficult problems？"Well，this is the result of using our brain for thinking of not-so-worthy things．Hunger of the mind can be actually satisfied through reading．Now why reading and not watching TV？Because reading has been the most educative tool used by us right from the childhood．Just like that to develop other aspects of our life，we have to turn to reading．You have innumerable number of books in this world which will answer all your"How to？"questions．The interesting part of the book is stored in your mind as a seed．Now this seed is unknowingly used by you in your future to develop new ideas．The same seed，if used many times，can help you link and relate a lot of things，of which you would have never thought in your wildest dreams!This is nothing but creativity．More the number of books you read，your mind will open up like never before．72．What is the function of the first paragraph？BA．To show humans are the most developed．B．To introduce the topic of the passage．C．To indicate people have different needs to satisfy．D．To explain why people need to read．73．What does the author mean by saying"When mind looses its freedom to grow，creativity gets a full stop．"AA．When mind keeps growing，creativity fully stops．B．When freedom is lost，creativity gets a full stop．C．When mind stops growing，creativity fully stops．D．When growing is lost，creativity gets a flail stop．74．The paragraph following the passage is probably aboutB．A．how the pre-historic man feeds his mindB．what other advantages reading bringsC．how to develop creativityD．how to satisfy your mind by watching TV75．The author tends to tell usC．A．reading can satisfy your all needs        B．reading can result from creativityC．reading can feed your mind              D．reading can realize your dreams．