英语听力：自然百科 行星旅行指南：火星 Mars—13

 You can make estimates of how much water had to have been flowing that carved these things, and you get numbers like 100, 200 Amazon rivers all cut loose at once, big, big amounts of waterfalls / across its surface. 

 

The other big attraction on Mars is the largest volcano, and highest mountain in the solar system. Olympus Mounts towers at an astounding¹ 17 miles, 3 times higher than Everest, its base covers more ground than the United Kingdom, and the massive caldera(火山口) at its submit could easily swallow Greater London, Paris and New York. 

 

Things tend to be big on Mars. I think in part that is because the planet has lower gravity. That is / when you pile up lava², you can pile it 3 times higher because the gravity is 3 times less before all starts to collapse³ on its own weight. 

 

Mars is a far more active world than previously⁴ thought. We see landslides⁵ of dust, and gullies(沟壑)freshly carved by outflows of mysterious fluids. And this peculiar⁶ region has been claimed as flash frozen sea, complete with fossil icebergs⁷. Likewise, there are glaciers⁸, geologically recent, but now buried beneath protective blanket of dust, waiting for the next change of the climate, still, most of defining surface features of Mars were carved away back in the good old days. 

 

Certainly, something happened in the early history of Mars that led to / great release of / water, and of course people wonder, without that much water, could there have been / ancient oceans? Could there have been an environment that was very much like life environments on the early earth. 

 

Early Mars was a different world, a world with a thicker atmosphere, with weather and water, possibly a vast / shallow northern ocean. This was really the time to go to Mars, when you did not need a spacesuit, perhaps just an oxygen tank and some warm clothes

 

1 astounding   

adj.使人震惊的vt.使震惊，使大吃一惊astound的现在分词)

参考例句：

• There was an astounding 20% increase in sales. 销售量惊人地增加了20%。
• The Chairman's remarks were so astounding that the audience listened to him with bated breath. 主席说的话令人吃惊，所以听众都屏息听他说。 来自《简明英汉词典》

2 lava   

n.熔岩，火山岩

参考例句：

• The lava flowed down the sides of the volcano.熔岩沿火山坡面涌流而下。
• His anger spilled out like lava.他的愤怒像火山爆发似的迸发出来。

3 collapse   

vi.累倒；昏倒；倒塌；塌陷

参考例句：

• The country's economy is on the verge of collapse.国家的经济已到了崩溃的边缘。
• The engineer made a complete diagnosis of the bridge's collapse.工程师对桥的倒塌做了一次彻底的调查分析。

4 previously   

adv.以前，先前（地）

参考例句：

• The bicycle tyre blew out at a previously damaged point.自行车胎在以前损坏过的地方又爆开了。
• Let me digress for a moment and explain what had happened previously.让我岔开一会儿，解释原先发生了什么。

5 landslides   

山崩( landslide的名词复数 )； （山坡、悬崖等的）崩塌； 滑坡； （竞选中）一方选票占压倒性多数

参考例句：

• Landslides have cut off many villages in remote areas. 滑坡使边远地区的许多村庄与外界隔绝。
• The storm caused landslides and flooding in Savona. 风暴致使萨沃纳发生塌方和洪灾。

6 peculiar   

adj.古怪的，异常的；特殊的，特有的

参考例句：

• He walks in a peculiar fashion.他走路的样子很奇特。
• He looked at me with a very peculiar expression.他用一种很奇怪的表情看着我。

7 icebergs   

n.冰山，流冰( iceberg的名词复数 )

参考例句：

• The drift of the icebergs in the sea endangers the ships. 海上冰山的漂流危及船只的安全。 来自《简明英汉词典》
• The icebergs towered above them. 冰山高耸于他们上方。 来自辞典例句

8 glaciers   

冰河，冰川( glacier的名词复数 )

参考例句：

• Glaciers gouged out valleys from the hills. 冰川把丘陵地带冲出一条条山谷。
• It has ice and snow glaciers, rainforests and beautiful mountains. 既有冰川，又有雨林和秀丽的山峰。 来自英语晨读30分（高一）