当前位置 > 首页 > 英语作文 > 小学英语作文 > 

Icebergs

作者:佚名     时间:2010-09-25     浏览:873
绿叶鸟网(www.lvyeniao.cn)原创整理的 > 考研英语作文   

Icebergs are among nature's most spectacular creations, and yet most people have nr seen one. A vague air of mystery envelops them. They come into being ----- somewhere ------in faraway, frigid waters, amid tderous 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 in darker hues. They are gracel, 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 have fallen over long ages of time. They embody snows that drifted down dreds, 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 suce, 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 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 compressed the lower ones. With time and pressure from above, the many all ice grains joined and changed to larger crystals, and ntually the deeper crystals merged into a solid mass of ice.


喜 欢

508

上一个:Plate Tectonics and Sea-floor Spreading
下一个:Topaz
绿叶鸟作文网地图 _ 一览精美作文文章
友情链接:
美文摘抄 -  美文欣赏 -  寓言故事大全 -  人生语录 -  微语录 -  语录大全 -  造句大全 -  一边一边造句 -  即使也造句 -  只要就造句 -  大学生成功创业案例 -  创业成功故事 -  创业资讯 -  生活小妙招大全 -  生活常识大全 -  健康常识 -  生活常识 -  写人的作文 -  优秀作文 -  小学生作文大全 -  好句子摘抄 -  句子赏析 -  优美句子摘抄 - 
假如内容还不错的话,就分享给朋友仔门吧