Because wild penguins only live in the colder parts of the southern hemisphere, most people have never visited them in their natural habitat. However, one can't help but burst into laughter at the sight of these black and white bowling pins shuffling side to side across the ice on their impossibly short legs. The funniest feature of the penguin is, no doubt, its walk, or "waddle." But it is this waddle that allows penguins to tolerate their bitterly cold habitat.

　　Scientists have long known that penguins need a lot of energy to keep moving. To waddle a given distance, penguins use twice as much energy as other creatures of the same size use to walk equally far. However, in order to survive in their harsh habitat, penguins must save as much energy as possible. Some people might wonder why the birds don't simply stop waddling and walk at a slower pace. Surprisingly, the penguins' walk allows them to save energy that would be wasted if they walked without waddling.

　　由于野生企鹅仅生长于南半球较寒冷的地带，因此大多数人都不曾造访过它们的自然栖息地。然而，当看到这些黑白相间的"保龄球瓶"拖着短得不能再短的腿，摇摇摆摆地在冰天雪地里穿梭时，任何人都会忍不住发出爆笑。企鹅最有趣的一项特征，莫过于他们走路的方式，或者说他们"摇摆行走"的样子。但正是靠着这种摇摇摆摆的样子，企鹅才得以承受其栖息地的酷寒气候。

　　科学家早已知道，企鹅的活动、行走需耗费极大的能量。同样一段距离，企鹅以其摇摆的方式来行走，所消耗掉的体能是其他同体型动物的两倍之多。然而，为了能在气候恶劣的栖息地存活，企鹅必须尽可能地节省能量。有些人可能并不懂，为什么企鹅不干脆停止摇摆，改成慢慢地走。出乎我们意料的是，企鹅摇摆着走，反而较常态行走更节省能量。

　　Vocabulary

　　1.penguin n. a seabird found in the southern hemisphere企鹅

　　The only animals we saw when we arrived in Antarctica were penguins and seals.

　　我们抵达南极洲时，惟一看到的动物就是企鹅和海豹。

　　2.burst into laughter / tears v. phr. to suddenly show emotion with laughter, tears, etc.突然(大笑/大哭)起来

　　Maria burst into tears when she heard the bad news.

　　玛丽亚听到这个坏消息时，突然大哭了起来。

　　3.tolerate v. to bear sth. difficult忍受；容忍

　　After Mr. Harris said he would not tolerate any more noise, there was complete silence in the classroom.

　　当哈里斯老师说他将不再容忍任何吵闹声时，教室里一片鸦雀无声。

　　4.bitterly adv. extremely or intensely, used to describe cold, sadness, etc.极度地；强烈地

　　Because the winds bring bitterly cold weather in the winter, very few people live here.

　　由于冬季冷风带来刺骨的寒气，因此只有极少的人在这里居住。

　　5.creature n. a living human or animal生物；动物

　　Whales must surely be the largest of all creatures on earth.

　　鲸鱼无疑是地球上最大的生物了。

　　6.pace n. speed速度；步调

　　The man was walking at quite a fast pace and his young son had difficulty keeping up with him.

　　这名男子走得飞快，他的小儿子没办法跟上他。

　　More Information

　　1.hemisphere n.半球

　　2.habitat n.栖息地；住所

　　3.shuffle v.拖着脚走；曳足而行

　　4.waddle n.摇摇晃晃地走；蹒跚地走(亦可作动词使用)