Icebergs are among natures most spectacular creations, and yet most people have never seen one. A vague air of mystery envelops them. They come into being ----- somewhere ------in faraway, frigid waters, amid 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 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 have 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 years 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 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 small ice grains joined and changed to larger crystals, and eventually the deeper crystals merged into a solid mass of ice.
雅思听力场景和词汇:图书馆场景
雅思词汇:饮食--蜜饯、酒
雅思考试词汇语法准备攻略
雅思常考十种场景词汇(2)
雅思词汇记忆方法谈(中)
雅思词汇:个人简历-品质
雅思词汇:饮食--冷饮、水果、蔬菜
ielts口语词汇:电影类别
雅思听力场景和词汇:新生报到场景
词汇语法学习与英语水平的提高
雅思词汇:会议词汇
雅词汇:数码相机规格
雅思词汇:信用卡相关用语
雅思分类词汇:报刊图书词汇
雅思听力场景和词汇:停车场景
雅思词汇:报纸用语
雅思词汇:交通和交通工具(上)
雅思词汇:公司企业部门名称
雅思词汇:个人简历-工作经历
雅思听力常考场景单词短语分类
雅思听力场景,词汇:选课场景
雅思听力场景和词汇:日程活动介绍场景
雅思词汇:家畜词汇
雅思分类词汇:交通相关词汇
雅思词汇:法庭与法律用语
雅思分类词汇:体育-足球
雅思词汇:宗教词汇
雅思词汇:标点符号
国人为何因‘单词’而折腰
雅思词汇快速记忆--词根
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英语教案 |
英语课件 |
英语试题 |
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