Lesson 18 Porpoises海豚
First listen and then answer the following question.听录音，然后回答以下问题。
What would you say is the main characteristic of porpoises?
There has long been a superstition among mariners that porpoises will save drowning men by pushing them to the surface, or protect them from sharks by surrounding them in defensive formation. Marine Studio biologists have pointed out that, however intelligent they may be, it is probably a mistake to credit dolphins with any motive of lifesaving. On the occasions when they have pushed to shore an unconscious human being they have much more likely done it out of curiosity or for sport, as in riding the bow waves of a ship. In 1928 some porpoises were photographer working like beavers to push ashore a waterlogged mattress. If, as has been reported, they have protected humans from sharks, it may have been because curiosity attracted them and because the scent of a possible meal attracted the sharks. Porpoises and sharks are natural enemies. It is possible that upon such an occasion a battle ensued, with the sharks being driven away or killed.
长期以来，海员中流传着一种迷信的说法，认为海豚会把快要淹死的人托到水面，救人性命；或在人们周围列队保护，使他们免遭鲨鱼伤害。海洋摄影室的生物学家 指出，无论海豚多么聪明，认为它们有救人的动机可能是错误的。当它们偶尔把一个失去知觉的人推到岸边时，更大的可能是出于好奇或游戏，就像它们追逐被船首 犁开的浪花一样。1928年，有人拍摄到了海豚像海狸一样把浸透水的床垫推上岸的情景。正如报道中所说，如果海豚保护人不受鲨鱼侵害，那么它们可能是出于 好奇；而鲨鱼可能是闻到了可以美食一顿的香味。海豚和鲨鱼是天然仇敌，双方可能随之发生搏斗，搏斗结果是海豚赶走或咬死鲨鱼。
Whether it be bird, fish or beast, the porpoise is intrigued with anything that is alive. They are constantly after the turtles, who peacefully submit to all sorts of indignities. One young calf especially enjoyed raising a turtle to the surface with his snout and then shoving him across the tank like an aquaplane. Almost any day a young porpoise may be seen trying to turn a 300-pound sea turtle over by sticking his snout under the edge of his shell and pushing up for dear life. This is not easy, and may require two porpoises working together. In another game, as the turtle swims across the oceanarium, the first porpoise swoops down from above and butts his shell with his belly. This knocks the turtle down several feet. He no sooner recovers his equilibrium than the next porpoise comes along and hits him another crack. Eventually the turtle has been butted all the way down to the floor of the tank. He is now satisfied merely to try to stand up, but as soon as he does so a porpoise knocks him flat. The turtle at last gives up by pulling his feet under his shell and the game is over.
海豚对凡是活的东西都感兴趣，不管是鸟、是鱼，还是野兽。它们经常追逐海龟，海龟则温顺地忍受着各种侮辱。一只小海豚特别喜欢用鼻子把海龟推到水面，然后 像滑水板一样把海龟从水池的这一边推到那一边。几乎每天都可以看到一只小海豚把鼻子顶入一只300磅重的海龟的硬壳下面，拼命地把它翻过来。这并非易事， 可能需要两只海豚合伙干才行。在另一场游戏中，当海龟游过水族馆时，第一只海豚从上方猛扑下去，用腹部撞击龟壳。这一下子把海龟撞下去好几英尺。海龟刚恢 复平衡，第二只海豚又冲过来猛击一下。这只海龟最终被撞到池底。此时的海龟，只要能站起来就满足了，但它刚站起来，就被一只海豚击倒。海龟终于屈服了，将 4条腿缩进壳内。游戏到此结束。
New words and expressions 生词和短语
porpoise
n. 海豚
mariner
n. 水手
shark
n. 鲨鱼
formation
n. 队形
dolphin
n. 海豚科动物
unconscious
adj. 不省人事
beaver
n. 海狸
ashore
adv. 上岸
waterlogged
adj. 浸满水的
scent
n. 香味
ensue
v. 接着发生
intrigue
v. 引起兴趣
indignity
n. 侮辱
snout
n. 口鼻部
shove
v. 硬推
aquaplane
n. 驾浪滑水板
oceanarium
n. 水族馆
swoop
v. 猛扑
belly
n. 腹部
equilibrium
n. 平衡
butt
v. 碰撞
crack
n. 重击
Notes on the text课文注释
1 however intelligent they may be, 不管它们有多聪明，这是一个让步状语从句。
2 as in riding the bow waves of a ship, 就像他们追逐被船首 犁开的浪花一样。
3 If , as has been reported, they have protected humans from sharks...
as 是关系代词，代替they have protected humans from sharks.
4 Whether it be bird,fish or beast...
这是一个让步状语从句，用的是虚拟语气形式。
5 for dear life,拼命地。
Lesson 18 课后练习和答案Exercises and Answer
