英语听力：探索发现 2013-01-09 冰河新新州 Ice Age Oasis—12

 They can grow more than two metres long and weigh as much as three men. But the giant tortoises of ice age North America were even larger. Florida does have tortoises today, but on a much smaller scale. This is the gopher tortoise. 

 

Tortoises are cold-blooded animals. They rely on external temperature to keep themselves warm. Although Florida is plenty warm enough for much of the year, during the winter months, it can get cold. So to survive the winter, gopher tortoises must burrow¹ and hibernate² underground. The colder it gets, the deeper into their burrow they go. 

 

Giant tortoises, however, can't burrow. And they sleep above ground. They need relatively³ warm temperatures all year round. The fact they were in Florida during the ice age means that paradoxically the climate must have been more stable and even milder than it is today. So we know something of the climate, but what about the vegetation and the landscape. How did that look 13,000 years ago? 

 

Today Florida is one of the wettest parts of the continent, especially the vast swampy⁴ area known as the Everglades. Flooded grasslands⁵ stretches as far as the eye can see.

1 burrow   

vt.挖掘(洞穴)；钻进；vi.挖洞；翻寻；n.地洞

参考例句：

• Earthworms burrow deep into the subsoil.蚯蚓深深地钻进底土。
• The dog had chased a rabbit into its burrow.狗把兔子追进了洞穴。

2 hibernate   

v.冬眠，蛰伏

参考例句：

• Bears often hibernate in caves.熊常在山洞里冬眠。
• Some warm-blooded animals do not need to hibernate.一些温血动物不需要冬眠。

3 relatively   

adv.比较...地，相对地

参考例句：

• The rabbit is a relatively recent introduction in Australia.兔子是相对较新引入澳大利亚的物种。
• The operation was relatively painless.手术相对来说不痛。

4 swampy   

adj.沼泽的，湿地的

参考例句：

• Malaria is still rampant in some swampy regions.疟疾在一些沼泽地区仍很猖獗。
• An ox as grazing in a swampy meadow.一头牛在一块泥泞的草地上吃草。

5 grasslands   

n.草原，牧场( grassland的名词复数 )

参考例句：

• Songs were heard ringing loud and clear over the grasslands. 草原上扬起清亮激越的歌声。 来自《现代汉英综合大词典》
• Grasslands have been broken and planted to wheat. 草原已经开垦出来，种上了小麦。 来自《简明英汉词典》