英语听力：自然百科 探索世界奥秘之Life in the Freezer (冰雪童话) Unit03

Huge though bergs may be, they are nonetheless usually on the move. But come the winter, sea ice forms around them and locks them solid. As winter progresses, so more and more of the sea freezes, spreading out from the margins¹ of the land like an immense skirt so that, in effect, the continent doubles in size. When the ice reaches its farthest extent, you have to travel hundreds of miles from the edge of the continent before you reach open water.

The annual formation of the sea ice is the greatest seasonal² change that takes place on this planet and it completely dominates the lives of Antarctic animals. Practically all of them are directly dependent upon the sea for their food, so year-round access to it is essential for their survival. In the summer, when the sea ice melts, they can reach the islands that were trapped in the ice and eventually the continent itself. But when the ice re-forms, they have to retreat north. So now, in winter, with the sea ice at its fullest extent, it's in the sea that we must look for life.

The southern ocean is extremely rich in food. Millions of penguins³ and seals and thousands of whales feed here. The majority of them rely on just one source of food-krill. Krill are small shrimp-like creatures about 6 centimeters long. In winter, they are dispersed⁴ widely, mostly under the ice, but in summer they assemble in vast swarms⁵, some of which may contain a billion individuals. They are the most numerous animals on earth. Their total weight far exceeds that of the total human population.

words and expressions

year-round : (a.) Existing, active, or continuous throughout the year全年的

krill: (n.) The collection of small marine⁶ crustaceans⁷ of the order Euphausiacea that are the principal food of baleen⁸ whales. 磷虾磷

1 margins   

边( margin的名词复数 )； 利润； 页边空白； 差数

参考例句：

• They have always had to make do with relatively small profit margins. 他们不得不经常设法应付较少的利润额。
• To create more space between the navigation items, add left and right margins to the links. 在每个项目间留更多的空隙，加左或者右的margins来定义链接。

2 seasonal   

adj.季节的，季节性的

参考例句：

• The town relies on the seasonal tourist industry for jobs.这个城镇依靠季节性旅游业提供就业机会。
• The hors d'oeuvre is seasonal vegetables.餐前小吃是应时蔬菜。

3 penguins   

n.企鹅( penguin的名词复数 )

参考例句：

• Why can penguins live in cold environment? 为什么企鹅能生活在寒冷的环境中？ 来自《简明英汉词典》
• Whales, seals, penguins, and turtles have flippers. 鲸、海豹，企鹅和海龟均有鳍形肢。 来自《现代英汉综合大词典》

4 dispersed   

adj. 被驱散的, 被分散的, 散布的

参考例句：

• The clouds dispersed themselves. 云散了。
• After school the children dispersed to their homes. 放学后，孩子们四散回家了。

5 swarms   

蜂群，一大群( swarm的名词复数 )

参考例句：

• They came to town in swarms. 他们蜂拥来到城里。
• On June the first there were swarms of children playing in the park. 6月1日那一天，这个公园里有一群群的孩子玩耍。

6 marine   

adj.海的；海生的；航海的；海事的；n.水兵

参考例句：

• Marine creatures are those which live in the sea. 海洋生物是生存在海里的生物。
• When the war broke out,he volunteered for the Marine Corps.战争爆发时，他自愿参加了海军陆战队。

7 crustaceans   

n.甲壳纲动物（如蟹、龙虾）( crustacean的名词复数 )

参考例句：

• These crustaceans provide a valuable food source for some fish. 这些甲壳纲动物是某些鱼类重要的食物来源。 来自《简明英汉词典》
• When the tide ebbs it's a rock pool inhabited by crustaceans. 退潮时，它便成为甲壳动物居住的岩石区潮水潭。 来自辞典例句

8 baleen   

n.鲸须

参考例句：

• Other baleen whales have splash guards too,but not like this.一些须鲸物种头顶也有护住喷水孔的构造，但并不长成这样。
• Baleen whales often appear in this region. Be careful!这一带经常有须鲸出没，要注意安全啊。