❶ Carrying Capacity 00：45 seconds
❷ An animal species needs to have enough resources, like food and water, to survive in any given environment. However, because resources are limited, only a certain number of animals of a particular species are able to survive in a given habitat. ❸ The greatest number a habitat can support is known as the carrying capacity. ❹ If nothing happens to disrupt or unbalance the relationship between the animal and its habitat, the carrying capacity will remain stable. However, a carrying capacity is not fixed. If there is a significant disruption, such as an environmental event that alters the amount of available resources in the habitat, the carrying capacity will change.
常见的表示定义的提示词有 refer to, known as, is, is called, etc.
❸中重复出现了标题Carrying Capacity，并且有非常明显的提示词known as 。结合内容，承载能力是指栖息地上所能承载最大的数量。因此，该句是定义句。
The greatest number of animals a habitat can support is called carrying capacity.
OK, ❶ so let’s talk about what happened to a certain type of insect, a moth, a red-and-black moth that lives in Europe. ❷ These moths eat a plant called Ragwort and they live in fields where the Ragwort plants grow. Now, there was a group of moth that lives in one of these fields and, for many years, there was a lot of Ragwort growing there. So the moth had plenty to eat and the total number of moth in the field stayed pretty much the same. ❸ But then one year it rained a lot less than usual and the Ragwort didn’t grow as well.
The result was that the moth didn’t get enough to eat and many didn’t survive but even the ones that did survive didn’t lay as many eggs as before. So that year the moth population in the field was quite a bit smaller. The next year, though, the amount of rainfall returned to normal and again many more Ragwort plants grew and, once again, there was a lot available for the moth to eat. So that year the moth population increased and the female moth laid many more eggs than the year before. And now, after all that rainfall and plant growth, there were just as many moth in the Ragwort field as there were before.
1 Example ：
❶ 中教授以red-and-black moth 来讲授Carrying Capacity的概念。
❷ 中，教授说道，red-and-black moth 以Ragwort为食，而体表蛾生存的地方有很多的Ragwort，因此就有许多的蛾子生活在这片区域，结果是这些蛾子的总数量是保持相对稳定的状态。❸中，教授讲到，有一年有特殊情况出现，雨水比平时少很多，结果导致Ragwort生长情况不好，因而蛾子就没有足够的食物来源，很多没能生存下来。过了一年，雨水恢复正常，有足够的Ragwort plants生长起来，又为蛾子提供了食物来源，结果是蛾子的数量增加了。
a moth, eat Ragwort, 数量稳定
Rain less，Rag. ×, M× survive
Rain normal, moth ↗
1 Example ：
Moth is a kind of insect that eats ragwort. Ragwort is a plant that grows in the field. Normally, the number of moth in the ragwort field is stable. But if there were a lot less rain in a year, ragwort wouldn’t grow well. Moth wouldn’t survive and even those that survived lay fewer eggs. So the number of moth would decrease. But if the rain went back to a normal level, the ragwort would grow well.
In the reading, the article talks about___❶___, (which means___❷___)
In the listening, the professor gives out one/ two example(s) to explain the title.
For instance, ___________❸____________.
The second is___________❹____________.
Therefore, by giving out this/these example(s), the professor tells us the meaning of ______❺______.(optional)
In the reading, it says that the greatest number of animals a habitat can support is called carrying capacity. Carrying capacity is not fixed. It changes according to the environment. The professor uses the relationship of moth and ragwort to illustrate this concept. Moth is a kind of insect that eats ragwort. Ragwort is a plant that grows in the field. Normally, the number of moth in the ragwort field is stable. But if there were a lot less rain in a year, ragwort wouldn’t grow well. Moth wouldn’t survive and even those that survived lay fewer eggs. So the number of moth would decrease. But if the rain went back to a normal level, the ragwort would grow well. Moth would have enough to eat and would lay more eggs. And the number of moth would also increase.
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