Icebergs
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 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 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 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 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.
雅思口语范文:A restaurant or café
雅思口语范文:An environmental problem
雅思口语素材:Father's Day(父亲节)
雅思口语范文:A happy event
雅思口语素材:International Women's Day(国际妇女节)
雅思口语范文:A party
雅思口语范文:A traditional festival
雅思口语素材:April Fool's Day(愚人节)
雅思口语素材:Earth Day(世界地球日)
雅思口语素材:好句推荐-人生如茶
雅思口语范文:Weather相关的问题
雅思口语素材:Shavuot(五旬节)
雅思口语范文:A letter
雅思口语素材:Easter Day(复活节)
雅思口语范文:A book you like
雅思口语范文:An ideal job
雅思口语范文:Getting news
雅思口语范文:Favorite shopping center
雅思口语范文:Learning English
雅思口语范文:Your favorite color
雅思口语素材:名人名言-亚里士多德名言
雅思口语天天练:口语中常见的"Not"
雅思口语天天练:形容“忙”的表达
雅思口语范文:A Kind of music
雅思口语范文:Food相关的问题
雅思口语范文:important invention
雅思口语素材:Shakespeare's Birthday(莎士比亚诞辰纪念日)
雅思口语范文:A piece of equipment
雅思口语范文:A school subject
雅思口语范文:Your favorite photograph
| 不限 |
| 英语教案 |
| 英语课件 |
| 英语试题 |
| 不限 |
| 不限 |
| 上册 |
| 下册 |
| 不限 |