科学家发现，世界上最濒危的两栖动物之一，长相奇异、永远微笑着的墨西哥钝口螈，也叫美西螈，在被放归于人工湿地后能够茁壮成长。

There are hundreds of thousands of Mexican axolotls in laboratories and home aquariums around the world, studied for their remarkable ability to regrow any lost limb. But in their native wetlands in Xochimilco in Mexico City, the population has been decimated by pollution and invasive species.

数十万只美西螈被饲养在全球各地的实验室和家庭鱼缸中，人们借此研究它们非凡的肢体再生能力。然而，在它们的原生栖息地，墨西哥城的索奇米尔科湿地，野生美西螈的数量因污染和外来物种的入侵而大幅减少。

Now, though, researchers who've bred axolotls in captivity have taken a major step towards bringing them back. The team released a small group at two sites in the city's wetland. They fitted the amphibians with radio trackers so they could follow their progress.

不过现在，圈养和繁育美西螈的研究人员向将它们放归自然的方向迈出了重要的一步。研究团队将一小群美西螈放归至墨西哥城湿地的两处地区。研究人员为它们装上了无线电追踪器，以便追踪它们的生长情况。

All 18 animals have survived, and a few that were recaptured had gained weight, showing that despite being raised in tanks, they were now hunting. It's early days, but if the wild axolotl can be saved in a city of more than 20 million people, scientists say that will be a symbolic success story.

被放归的 18 只美西螈全部存活了下来，其中一些被重新捕获的个体的体重也增加了，这表明尽管这些美西螈之前被圈养在水缸中，但它们现在已开始进行捕猎。虽然实验尚处在早期阶段，但科学家表示，如果野生美西螈可以在一个人口超过 2000 万的城市中生存下来，那这将是一个标志性的成功案例。

词汇表

remarkable 非凡的，引人注目的
limb 肢体
wetlands 湿地
decimated 大幅削减，毁灭
in captivity 圈养
radio trackers 无线电追踪器
raised 饲养，养育

听力练习

一、听第一遍音频，回答问题。

1. What is the overall tone of this report?
a. positive
b. negative
c. neutral

二、用一分钟阅读下列问题，然后听第二遍音频并回答问题。

1. There are small numbers of axolotls, both in captivity and in the wild.
a. True
b. False
c. Not given

2. There are fewer axolotls in their natural habitat because of _______ and _______.

3. How did the researchers follow the axolotls' progress once released?
a. They bred them in captivity.
b. They put them in the wetland.
c. They attached radio trackers to them.

4. What is the significance of the axolotls gaining weight?
a. It means they can hunt and feed themselves in the wild.
b. It means there is enough food in the wetlands.
c. It means the researchers must restrict their food supply.

5. Scientists believe the axolotls will be saved from extinction.
a. True
b. False
c. Not given

三、听第三遍音频，将句子补充完整。（提示：可以反复听，直到听清楚每一个词）

1. Now, ________________, researchers who've bred axolotls in captivity have taken a major step towards bringing them back.

2. They fitted the amphibians with radio trackers ________________ follow their progress.

答案

一、听第一遍音频，回答问题。

1. What is the overall tone of this report?

a. Positive. The research had a positive result. All 18 animals have survived, and a few that were recaptured had gained weight, showing that despite being raised in tanks, they were now hunting.

二、用一分钟阅读下列问题，然后听第二遍音频并回答问题。

1. b. False. There are many in captivity. There are hundreds of thousands of Mexican axolotls in laboratories and home aquariums around the world.

2. There are fewer axolotls in their natural habitat because of pollution and invasive species. 

3. c. They attached radio trackers to them. They fitted the amphibians with radio trackers so they could follow their progress.

4. a. It means they can hunt and feed themselves in the wild. A few that were recaptured had gained weight, showing that despite being raised in tanks, they were now hunting.

5. c. Not given. The report says if the wild axolotl can be saved in a city of more than 20 million people, scientists say that will be a symbolic success story, but this is conditional and hypothetical. There is no mention that the scientists believe the axolotls will be saved from extinction.

三、听第三遍音频，将句子补充完整。（提示：可以反复听，直到听清楚每一个词）

1. Now, though, researchers who've bred axolotls in captivity have taken a major step towards bringing them back.

2. They fitted the amphibians with radio trackers so they could follow their progress.