評論
打印
Listen to a conversation between a student and his biology professor.
聽一段學生和生物學教授的對話。
Well, you know, I'm reading the papers about whales, and the path they travel as they swim through the ocean, their migration patterns.
你知道的，我正在看關于鯨魚的論文，關于它們游過海洋的旅行軌跡，它們的洄游模式。
Yes, I remember.
對，我記得。
Well, I was thinking about it, and I realized I don't understand how they hold their breaths under water.
我正在想這件事，我發現我不明白它們怎么在水下閉氣的。
It's a little crazy for me to be writing a paper about migration patterns without actually knowing how they stay underwater for so long.
讓我寫一篇關于它們洄游模式的論文，但我實際上卻不知道它們怎么在水底待這么長時間的，這有點瘋狂。
Did you do any research to find out how they do it?
你有沒有查過資料來弄明白它們怎么做到的？
Yeah, I did.
我有。
I searched on the Internet, and there was a lot of information about whales, their habitats, the way they communicate, you know, their songs.
我在網上搜索過，網上有很多關于鯨魚的信息，它們的棲息地，它們的交流方式，你知道的，它們的歌聲。
But if there was anything about whales and how they hold their breaths, I missed it.
但假如真的有關于鯨魚怎么憋氣的信息，我一定是看漏了。
I've got a bunch of books. Actually, I've got so much information, it's a little overwhelming.
我有一大摞書。事實上我掌握了大量的信息，有點太多了。
I'm surprised that there is nothing about it in any of those books.
我很驚訝在這些書里竟然沒有與此相關的信息。
Well, to be honest, I've only skimmed them so far.
坦白說，我才剛把它們粗看了一遍。
I'm still working on finding sources.
我還在尋找信息。
Ok, I know I encourage everyone in class to look at a substantial number of sources, but I don't want you to get overwhelmed.
好了，我明白我鼓勵班上的每個人去看大量相關資料，但我不想你看太多以致無從下手。
Looking at a number of sources gives you a good knowledge base, but students only have a limited amount of time to work on each paper.
通過看一定數量的資料，你會得到一個很好的知識儲備，但學生在每份論文上都只有很有限的時間。
I don't expect you to read a dozen of books on whales for this assignment. Focus on just a few.
我不希望你為了這次作業看一大堆關于鯨魚的書。集中看幾本就行了。
Ok, thanks.
好的，謝謝。
You know, since you're already here, I can give you a quick summary of how whales hold their breaths underwater.
既然你已經來了，我能給你簡單講講鯨魚是怎么在水下閉氣的。
It's just a matter of certain adaptations in their anatomies, specifically in their circulatory system.
這不過是它們身體構造里的一些適應性進化，準確地說是它們的循環系統。
So, the blood flow was what makes the difference?
所以血流是關鍵？
Yes, and in a couple of ways.
對，通過不同的方式。
First, blood makes up a larger share of a whale's weight than any other mammals.
首先，血液在鯨魚體重中占的比重事很大的，比任何其它哺乳動物都要大。
So they can store more oxygen because they have more blood?
所以鯨魚能儲更多的氧，就因為它們的血量更多？
Yes, but that's only part of it.
對，但這只是一部分原因。
They also have a greater capacity than land animals to store oxygen in their blood.
它們在血內儲氧的能力比陸生動物高出許多。
So how does having more oxygen in their blood help them stay underwater longer?
那么，擁有更多的血液是怎么幫助它們在水下待得更久的？
It's the way the whale's blood carries oxygen to the rest of its body.
這是靠鯨魚血液將氧氣運輸到身體其它部分的方式。
Whales carefully conserve their oxygen when underwater in a couple of ways.
當在水下時，鯨魚通過不同的方法謹慎地儲氧。
When a whale dives, its metabolic weight drops, causing its heart beat to slow down.
當鯨魚潛入水中時，它的代謝體重會下降，心跳隨之減緩。
And the blood flows to its muscles and some of its none-vital organs, like its kidneys, is also cut off.
而且通向肌肉和一些非要害器官（如腎臟）的血流也停止了。
Whales muscles and none-vital organs are able to function without oxygen for an extended period of time.
鯨魚肌肉和非要害器官能在缺氧情況下持續運作一段時間。
I see, well, now I can concentrate on my topic.
我懂了，現在我我能專注于我的課題了。
