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Now listen to a part of lecture on the topic you just read about.
現(xiàn)在來聽一段有關(guān)你剛剛讀到的話題的演講。
Sure, there are some benefits to plant genetically modified trees, but, are these trees really as great as they first sound?
當(dāng)然，種植轉(zhuǎn)基因的樹木有一些好處，但是，這些樹木真的像它們開始聽起來那么好嗎？
When you examine the subject closely, there are some serious problems and costs associated with using genetically modified trees.
當(dāng)你仔細(xì)檢查這個(gè)主題時(shí)，有一些與轉(zhuǎn)基因樹木有關(guān)的嚴(yán)重的問題和花費(fèi)。
First, genetically modified trees may be resistant to one particular condition.
首先，轉(zhuǎn)基因樹木也許會(huì)對一種特殊的環(huán)境有抵抗力。
But that doesn't necessarily ensure their survival.
但那不能保證它們的存活。
You see, a typical non-modified tree population is genetically diverse.
你看，一個(gè)典型的非轉(zhuǎn)基因樹種是基因多樣化的。
That means that for most threatening conditions, for climate, insects and other pests, whatever,
那意味著對于大多數(shù)危險(xiǎn)的環(huán)境，如氣候、昆蟲和其它害蟲，不管什么，
there will be at least some individual trees of any given species of tree that are resistant.
無論哪個(gè)樹種至少會(huì)有一些個(gè)體樹木是有抵抗力的。
So even if most of one kind of tree are killed, those few resistant ones will survive and ensure the survival of that species of tree.
所以即使一種樹的大部分被殺死了，那些少數(shù)有抵抗力的會(huì)存活下來并保證該樹種的存活。
But genetically modified trees are genetically much more uniform.
但是轉(zhuǎn)基因樹木基因上更統(tǒng)一。
So if they're exposed to an environmental challenge they haven't been designed for, they'll all die.
所以如果它們暴露在一個(gè)它們沒有為其而設(shè)計(jì)的環(huán)境挑戰(zhàn)里，它們都會(huì)死。
So if the climate changes, or a new pest invades the area, the genetically modified trees will likely be completely wiped out.
所以如果氣候變化了，或者一個(gè)新的害蟲入侵該地區(qū)，轉(zhuǎn)基因樹木就可能會(huì)全部被消滅。
Now as to the second point, there are hidden costs associated with growing genetically modified trees.
現(xiàn)在關(guān)于第二點(diǎn)，種植轉(zhuǎn)基因樹木有著與其有關(guān)的隱藏消費(fèi)。
You see, the company that genetically modify the tree tends to charge tree farmers much more for its seeds than unmodified tree seeds would cost.
你看，從基因上改變樹木的公司常常為樹種收樹農(nóng)更多的錢，比起非轉(zhuǎn)基因的樹種。
Also, after you've grown the tree, you can't just collect the seeds and plant the new tree for free.
而且，在你種了樹之后，你不能僅僅收集種子免費(fèi)種植新樹。
By law, you have to pay the company every time you plant.
法律上，你每次種植的時(shí)候必須付錢給公司。
And finally, genetically-modified trees might actually cause even more damage to the local wild trees.
最后，轉(zhuǎn)基因樹木也許真的會(huì)引起對當(dāng)?shù)氐囊吧鷺淠編砀嗟膫Α?/div>
You see, genetically modified trees often grow more aggressively than natural trees do.
你看，轉(zhuǎn)基因樹木通常比自然樹木的生長更快速。
And, genetically modified trees are typically planted among natural trees.
而且，轉(zhuǎn)基因樹木通常是種植在自然樹木中間的。
As a result, the genetically modified trees out-compete the native trees for resources, sunlight, soil nutrients, and water, eventually crowding out the natural trees.
所以，轉(zhuǎn)基因樹木在資源--陽光、土壤營養(yǎng)和水上超過了原生樹木，最終排擠自然樹木。
