英语听力文摘 English Digest 148、像猪一样快乐

　　D: Congratulations on completing your PhD in Zoology¹ this week, Yael. That makes six advanced degrees for you and eleven for me.
Y: Well, we want to make sure Moment of Science listeners know they're getting only the best information.
D: You must be proud.
Y: I'm happy as a pig in mud.
D: Hey, there's a good moment of science.
Y: Why are pigs happy?
D: No, why do pigs roll in mud? I mean, you'd never catch me doing that!
Y: But I have seen you sweating.
D: Well, I guess so . . .
Y: Ever seen a pig do that?
D: Have I seen a pig sweat? Well . . . I guess not. But what's your point?
Y: Pigs are doing the same thing when they roll in mud that we're doing when we sweat. They're staying cool.
D: Staying cool?
Y: Sure. Humans get rid of excess heat by sweating. When the sweat evaporates it carries heat energy away from your body, which is why a sudden breeze feels cold when you are wet. Pigs don't have sweat glands². They have to add moisture to their skins in order to get it to evaporate and take away heat.
D: And mud has moisture in it.
Y: It sure does; otherwise it would be dry dirt. Anyway, mud may be a pig's only option if it's inside a pen. If there were water to splash in, the pig might choose that to cool off.
D: And that's something even people do!
Y: At every swimming pool in town.

1 zoology   

n.动物学，生态

参考例句：

• I would like to brush up my zoology.我想重新温习一下动物学。
• The library didn't stock zoology textbooks.这家图书馆没有动物学教科书。

2 glands   

n.腺( gland的名词复数 )

参考例句：

• a snake's poison glands 蛇的毒腺
• the sebaceous glands in the skin 皮脂腺