[新东方背诵文选80篇：44从冰山中获取淡水ObtainingFre]44 Obtaining Fresh Water from Icebergs The concept of obtaining fresh water from icebergs that are towed to populated areas and arid regions of the world was on...+阅读

37 Icebergs

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

Objects of sheerest beauty they he 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 or in darker hues. They are graceful, stately, inspiring -- in calm, sunlight 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 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 he fallen over long ages of time. They embody snows that drifted down hundreds, or many thousands, 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 depths over 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 bee tiny grains of ice. When new snow fell on top of the old, it too turned to 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 pressed the lower ones. With time and pressure from above, the many small ice grains joined and changed to larger crystals, and eventually the deeper crystals merged into a solid mass of ice.

冰山

冰山是大自然最壮观的创造之一，但大多数人却从未看到过冰山，一种朦胧神秘的气氛笼罩着它们。 冰山形成于久远的、寒冷的水体中，而且伴随着雷声轰鸣般的嘈杂和水花汹涌的风暴，但却无人耳闻目睹。 冰山仅存在短短的一段时间就慢慢地悄无声息地融化掉。 冰山具有最纯粹的美，人们如是说。 冰山呈现出千姿百态，可能白得耀眼，或者是闪耀着蓝色、绿色或紫色的玻璃般的光芒，或浓或淡。 它们在平静的阳光照耀的海水中显得优雅堂皇，令人浮想联翩。 但是人们亦把冰山称为恐怖的和危险的。 它们的确如此--在夜间，雾天和风暴肆虐时。 即便是在晴朗的天气里，与它们保持一段安全距离也是明智的。 冰山的大部分体积稳藏于水下，因此其水下部分的伸展远远超过可见的顶部。 冰山也可能出人意料地翻滚，剧烈地搅动周围的水体。 冰山是冰川的一部分，从冰川断裂漂流进水中，一段时间后融化。 今天的冰山由多年前降落的雪花形成。 它们的体内是数百年，或数千年，有时甚至是数百万年前的降雪。 这些雪花落在极地或寒冷的山上，仅有少量融化或根本不融化，这样经过许多年或许多世纪后积累了巨大的深度。 由于每年的雪花积累在表面之上，蒸发和融化使得雪花慢慢失去其羽状尖端而变成微小的冰粒。 当新的雪花降落到旧的表面上，也变成了冰粒。 因而雪花覆盖层和冰粒层层堆积起来直到如此之大的厚度以致较上层的重量压缩较下层。 在时间和压力的作用下，许多小冰粒结合到一起变成更大的晶体，最终较底层的晶体合并成庞大而坚固的冰块。

以下为关联文档：

新东方背诵文选80篇：55创造颜色CreatingColors55 Creating Colors There are two ways to create colors in a photograph. One method, called additive, starts with three basic colors and adds them together to pr...

新东方背诵文选80篇：46视觉Vision46 Vision Human vision like that of other primates has evolved in an arboreal environment. In the dense plex world of a tropical forest, it is more important to...

新东方背诵文选80篇：11考古学Archaeology11 Archaeology Archaeology is a source of history, not just a humble auxiliary discipline. Archaeological data are historical documents in their own right, not...

新东方背诵文选80篇：08美国革命AmericanRevolution08 American Revolution The American Revolution was not a revolution in the sense of a radical or total change. It was not a sudden and violent overturning of th...

新东方背诵文选80篇：48细菌Bacteria48 Bacteria Bacteria are extremely small living things. While we measure our own sizes in inches or centimeters, bacterial size is measured in microns. One micr...

英语科普文选：LocalAreaNetwork局域网Local Area work There are two categories of works: local area works (LANs) and wide area works (WANs). Here I'd like to mainly talk about LAN. A LAN is a system...

新东方老师谈句型的灵活运用句子也是如此，我们提倡简炼，但不是说都用简单句。有人认为在写作考试中，采用简单句、短句、容易掌握，不在会出错，因而也最保险。这话没有错，但简单句用得太多，造成简单句的堆彻实际...

新东方名师谈考研英语完形填空的复习方法考研的完形填空往往被很多考生所忽视，特别是在临考之前的时候。但事实上，考研完形如果复习的好，其收获绝对不只是那20道题目10分。对于完形的复习，分为以下几个方面： 首先是词汇...

新东方靳萌点评2008考研翻译本次考试试题来源于Mayo W. Hazeltine所写的一篇学术评论，主题是关于达尔文在现代科学中的地位。 In his autobiography，Darwin himself speaks of his intellectual powers w...