2017年6月英语六级阅读理解练习题：自然科学

　　Icebergs are among nature's most spectacular creations,and yet most people have never seen one.A vague airof mystery envelops them.They come into being-somewhere-in faraway,frigid waters,and thunderous noise and splashing turbulence,which in most cases no one hears or sees. They exist only a short time and then slowly waste away just as unnoticed.

　　Objects of sheerest beauty,they have been called.Appearing in an endless variety of shapes,they may be dazzlingly white,or they may be glassy blue,green,or purple,tinted faintly of darker hues(颜色).They are graceful,stately(宏伟的),inspiring in calm,sunlit seas.

　　But they are also called frightening and dangerous,and that they are-in the night,in the fog,and in storms.Even in clear weather one is wise to stay a safe distance away from them.Most of their bulk is hidden below the water,so their underwater parts may extend out far beyond the visible top.Also,they may roll over unexpectedly,churning(剧烈搅动)the waters around them.

　　Icebergs are parts of glaciers that break off,drift into the water.float about awhile and finally melt.Icebergs afloat today are made of snowflakes that have fallen over long ages of time.They embody snows that drifted down hundred,or many thousand,or in some cases,maybe a million years ago.The snows fell in polar-regions and on cold mountains,where they melted only a little or not at all and so collected to great depthsover the years and centuries.

　　As each year's snow accumulation lay on the surface,evaporation and melting caused the snowflakes slowly to lose their feathery points and become tiny grains of ice.When new snow fell on top of the old,it too turned into icy grains.So blankets of snow and ice grains mounted layer upon layer and were of such great thickness that the weight of the upper layers compressed the lower ones.With time and pressure from above,themany small ice grains joined and changed to larger crystals,and eventually the deeper crystals merged intoa solid mass of ice.

　　1.The author states that icebergs are rarely seen as they appear in_______________of the world.

　　2.From the passage,we can know that the shape of icebergs is___________________.

　　3.According to the passage,icebergs are scary and dangerous because they are likely to_______________________suprisingly.

　　4.What glaciers become when they break off and drift into the water?

　　5.What are the major factors in the process of the many small ice grains being merged into icebergs?

　　答案：

　　1.[faraway(distant/remote)waters(regions/areas)]

　　[定位]根据icebergs are rarely seen查找到第1段笫3句。

　　解析：题目中的appear in与of the world表明空格处需填入表地点的名词。原文开篇提到大部分人都没有见过冰山，从第3句可知，冰山形成于faraway, frigid waters，因此答案为faraway waters，也可以把faraway同义改写成distant或remote，或者把waters(水域)用regions或areas代替。

　　2.[in an endless variety of shapes/various/different]

　　[定位]根据shape查找到第2段第2句。

　　解析：题目需要表语成分。从原文该句可知冰山的形状各异，因此题目的答案可用appearing后的介词短语作答，也可以简要概括为various或different。

　　3.[roll over//turn over]

　　[定位]根据scary and dangerous和surprisingly查找到第3段第1句及最后一句。解析：题目需填入动词原形，表明冰山可怕的原因。原文第3段介绍了冰山的可怕之处，最后两句是原因所在。题目空格前的are likely to与原文最后一句的may是同义表达，所以答案为may后的动词词组。

　　4.[Icebergs.]

　　[定位]根据when从句的内容定位到第4段第1句。

　　解析：题目中的when从句是原文that定语从句的部分内容，原文句首的“Icebergs are parts of glaciers...”表明了冰山是由冰川的一部分形成，因此可知答案是Icebergs。

　　5.[Time and pressure(from above).]

　　[定位]根据small ice grains和merged into icebergs查找到最后一段最后一句。

　　解析：原文用With短语表达了众多小冰粒是怎么样形成大块坚冰的，也就是题目所询问的主要因素，因此答案为with后的宾语。