托福口语练习 说明龙珠果和马铃薯是如何抵抗昆虫侵害的

Using points from the lecture, explain how the passion plant and the potato plant defend themselves from insects.

请用课上的观点解释说明龙珠果和马铃薯是如何抵抗昆虫侵害的。

Listen to part of a lecture in a biology class.

请听生物课上的部分内容。

We all know that insects like to eat plants.

我们都知道昆虫喜欢吃植物。

But some plants are able to develop ways to protect themselves from insects.

但是有些植物进化出了抵抗昆虫侵害的方法。

Today I'm gonna talk about some ways plants defend themselves.

今天我要讲一讲植物保护自己的一些方法。

Now, some plants have physical features that prevent insects from landing on them.

有些植物具有的体貌特征能够防止昆虫降落在它们身上。

Like the passion plant, for example, its leaves have little spiky¹ hairs all over them.

就像龙珠果一样，它的叶子上长满了尖刻的毛。

They're like spikes², sticking out of the plant that are so numerous and dense³

这些毛就像钉子一样突出在植物表面，数量繁多且生长茂，

that they prevent insects from landing on the leaves.

它们能够阻止昆虫飞落在叶子上。

Basically there're just no room for the insects to land.

基本上根本没有地方可以让昆虫降落。

And since insects can't land on the leaves they can't eat them.

既然昆虫无法落在叶子上，它自然无法吃了它们。

So the little hairs serve as a physical feature that help protect passion plant from insects.

所以，这些毫毛就是保护龙珠果不受昆虫侵害的体貌特征。

All right! But other plants protect themselves using chemical defenses, like the potato plant.

好了！不过另一些植物会用化学手段来保护自己，比如马铃薯。

The potato plant is able to release a chemical throughout its leaf system whenever an insect attacks it, starts eating the leaf.

无论什么时候昆虫对它进行攻击，开始吃它的叶子，马铃薯都能通过叶系统释放出一种化学物质。

So, say an insect starts eating a potato plant's leaf,

假设一只昆虫开始吃马铃薯的叶子，

that will cause the plant to react by releasing a chemical throughout its leaf system.

这会使植物以通过叶系统释放化学物质的方式来做出反应。

The insect swallows this chemical as it eats.

昆虫在食用叶子的过程中也吞下了这种化学物质。

And this chemical discourages the insect from wanting to eat more of the plant.

而这种化学物质会让昆虫不想再吃这种植物了。

How? Well, the substance makes the insect feel full, like it's already had enough to eat.

为什么？因为这种物质会让昆虫有饱腹感，就像它已经吃得够多了一样。

The insect no longer feels hungry so it stops eating the plant.

昆虫觉得不饿了就会停止进食。

So, by emitting this chemical, the potato plant protects itself from insects.

所以，通过释放化学物质，马铃薯能够从昆虫的侵害中保护自己。

1 spiky   

adj.长而尖的，大钉似的

参考例句：

• Your hairbrush is too spiky for me.你的发刷，我觉得太尖了。
• The spiky handwriting on the airmail envelope from London was obviously hers.发自伦敦的航空信封上的尖长字迹分明是她的。

2 spikes   

n.穗( spike的名词复数 )；跑鞋；（防滑）鞋钉；尖状物v.加烈酒于( spike的第三人称单数 )；偷偷地给某人的饮料加入（更多）酒精（ 或药物）；把尖状物钉入；打乱某人的计划

参考例句：

• a row of iron spikes on a wall 墙头的一排尖铁
• There is a row of spikes on top of the prison wall to prevent the prisoners escaping. 监狱墙头装有一排尖钉，以防犯人逃跑。 来自《简明英汉词典》

3 dense   

a.密集的，稠密的，浓密的；密度大的

参考例句：

• The general ambushed his troops in the dense woods. 将军把部队埋伏在浓密的树林里。
• The path was completely covered by the dense foliage. 小路被树叶厚厚地盖了一层。