『新东方在线托福口语』为托福考生准备了ETS托福TPO/Official 43 Task 3口语练习：Population Changes &nbsp;
Populations of li原文题目答案解析，TPO/Official 43 Task 3口语原文范文音频翻译。

托福TPO/Official 43 Task 3口语原文独立/综合口语题目答案解析-范文音频翻译-新东方托福官方网校手机版

旁白：现在在生物课上听一段关于这个话题的讲座。

Narrator: Now listen to part of a lecture on this topic in a Biology class.

教授：想象一下，有一群老鼠生活在一个广阔的田野里，猫头鹰生活在附近。

Professor: Imagine there's a group of mice living in a large field and the owls living nearby.

所以在任何给定的时间里，老鼠的数量取决于该地区的猫头鹰数量。

so the number of mice there are at any given time depends upon the number of owls in the area.

因为在这个地区有更多的猫头鹰吃老鼠，

Since there are more owls in the area to eat the mice,

你认为老鼠的数量会发生什么变化？

what do you think will happen to the number of mice?

这个数字会下降，会有更少的老鼠。

the number would drop, there'd be fewer mice.

we can use rabbits to help understand this one.

假设有一群兔子生活在一个地区。

Imagine a population of rabbits living in an area.

在寒冷的冬天过后，这些兔子通常会马上开始生育幼崽，

These rabbits usually start having their young at the end of winter after the cold winter weather has gone,

它们一直在繁殖，直到第二年冬天，

and they keep reproducing until the following winter,

在寒冷的冬季天气持续期间它们将停止繁殖。

when they will stop again while the cold winter weather lasts.

你知道，天气比平常暖和的更早。

and you know it starts getting warm much earlier than usual.

the rabbits can start reproducing much earlier.

这意味着该地区的兔子至少会多一个繁殖周期，

That means the rabbits in that area will have at least one extra reproductive cycle.

因此这一区域的兔子数量会增加很多。

So the number of rabbits in that area would increase a lot.

Population Changes &nbsp;
Populations of living beings are constantly changing The number of humans, animals, insects, or plants living in a given area can vary because of two kinds of factors: biotic and abiotic. Biotic factors are living factors that can influence the size of populations, such as predators or other species competing for food. Abiotic factors are nonliving things in the surrounding environment that can cause population changes, such as weather or sunlight. Biotic and abiotic factors cause continual changes in the number of individuals that make up a population of organisms.&nbsp;&nbsp;
 
<img src="/upload/image/1516854491286.jpg">
 &nbsp;
 Using the examples of mice and rabbits from the lecture, describe the two different types of factors that can cause population changes.
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