新概念第四册课文翻译及学习笔记：Lesson18【课文】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 photographed 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.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.RALPH NADING HILL Window in the Sea【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【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，相当于no matter how intelligent they may be。
no matter what/how/who/which/where =whatever/however/whoever/whichever/wherever例句：Whatever you say, I will not change my mind. = No matter what you say, I will not change my mind.不管你说什么，我都不会改变主意的。
2.credit sb with sth，把某事归功于某人。
If people credit someone with an achievement or if it is credited to them, people say or believe that they were responsible for it.例句：Until now I've always credited you with more sense.在这以前，我一直都认为你不至如此糊涂。
3.out of curiosity，出于好奇。
You use out of to say what feeling or reason causes someone to do something. out of+名词：出于……，由于……。
例句：He has been taking care of her out of the sense of guilt.出于负罪感，他一直在照顾她。
4.as in riding the bow waves of a ship，就像它们追逐被船首犁开的浪花一样。
5.If, as has been reported, they have protected humans fromsharks...，as是关系代词，代替they have protected humans from sharks。
6.a battle ensued，随之发生搏斗。
If something ensues, it happens immediately after another event, usually as a result of it.继而发生，接着。
例句：Bitter arguments ensued from this misunderstanding.这一误会引发了激烈的争论。
7.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。
8.be intrigued with，对……感兴趣。
①intrigue (with sb) gainst sb：(联合某人)对某人搞阴谋诡计。
例句：She was intriguing with her sister against her mother.她和妹妹串通捣鬼跟母亲作对。
②intrigue sb，激起某人的兴趣。
例句：What you say intrigues me; tell me more.你说的很有意思，多给我讲些吧。
9.submit to，屈服，屈从于。
①If you submit to something, you unwillingly allow something to be done to you, or you do what someone wants, for example because you are not powerful enough to resist.屈服于。
例句：She refused to submit to his control.她不屈服于他的控制。
②If you submit a proposal, report, or request to someone, you formally send it to them so that they can consider it or decide about it.递交。
例句：Please submit your application form in quadruplicate.请交申请表一式四份。