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Listen to part of a talk in a botany class.
請聽一段植物學(xué)課上的演講。
OK. So we've talked about some different types of root systems of plants, and I've shown you some pretty cool slides,
我們已經(jīng)講過一些不同種類的植物的根系，我給你們看了一些很酷的幻燈片，
but now I want to talk about the extent of the root system—the overall size of the root system...the depth.
但我現(xiàn)在想說一下根系的長度——根系的總尺寸，深度。
I want to tell you about one particular experiment. I think you're going to find this pretty amazing.
我要跟你們講一個特別的實驗。我想你們會覺得很驚奇。
OK. So there was this scientist...this very meticulous scientist decided that the best place to see a whole root system—
好了。曾經(jīng)有一個科學(xué)家，這個非常謹(jǐn)慎的科學(xué)家認(rèn)為，最適合觀察一整個根系的地方——
to actually see how big the entire system got—the best place would be to grow it...where?
真正地觀察整個系統(tǒng)能長到多大——，最好把它種在......哪里？
Um, water?
水里嗎？
In water. So he took rye plants—it was rye plants—and he started growing them in water.
在水中。他取了黑麥植株——是黑麥——然后開始在水里種植。
Now, you've all heard of growing stuff in water before, right?
你們以前都聽過在水里中東西，對吧？
It's done commercially, right? Uh, like to grow vegetables and flowers?
是商業(yè)種植，對嗎？比如種植蔬菜和鮮花？
Right. They grow all kinds of commercial crops in water.
對的。他們在水里種植各種商業(yè)作物。
So, if you're growing things in water, you can add the fertilizer.
所以，如果你要在水里種東西，你可以加入肥料。
What do you need to do to that water besides put fertilizer in it? Anyone ever actually tried to grow plants in water?
除了在水里加入肥料還要對水做些什么？有人試過在水里種植物嗎？
You must bubble water through it. Bubble gas through it. I'm sorry, you must bubble gas through it.
你得往里面充入水。充入氣體。說錯了，是充入氣體。
So, gas, you have to bubble through. Think about the soil we talked about last week, about growing plants in soil.
所以你得往里面充氣。想一想我們上周說過的土壤，在土壤中種植植物。
Think about some of you who have killed your favorite houseplants, 'cause you loved them too much.
想一想你們誰殺死了自己最愛的室內(nèi)植物，因為溺愛。
If you overwater, why do your favorite houseplants die?
如果你澆水過多，你最愛的室內(nèi)植物就會死，為什么？
Oh, no oxygen.
哦，缺氧。
Not enough oxygen for the roots...which do what twenty-four hours a day in all seasons?
根部沒有足夠的氧氣，一年四季每天都在做的是什么？
Respiration?
呼吸？
Respire...respiration...they breathe.
植物呼吸，呼吸，它們會呼吸。
So, if you just stick rye plants in water, it doesn't make a difference how much fertilizer you add,
所以，如果你只是把黑麥植株插入水中，加入多少肥料并不重要，
you also need to bubble gas through the water, so they have access to that oxygen.
你還需要往水中充入氣體，所以它們才能獲得氧氣。
If they don't have that, they're in big trouble.
如果沒有氧氣，它們麻煩就大了。
OK. So this guy—this scientist—grew a rye plant in water so he could see the root system how big it got—its surface area.
所以這個家伙——這個科學(xué)家——在水中種了一株黑麥以便他觀察根系能長到多大——它的表面部分。
I read about this and the book said one thousand kilometers of roots. I kept thinking: this has to be a mistake.
我閱讀過這個，書上說，根有一千千米長。我一直在想：這肯定是個錯誤。
It just doesn't make any sense to me that...that...that could be right.
我覺得沒道理，那不是對的。
But that's what all the books have, and no one's ever corrected it.
但是所有的書上都是那樣寫的，沒有人修改過。
