英语听力精选进阶版 7174（在线收听）

Background: 科学家最新发现了两亿五千年前类似恐龙的动物足迹。这一发现将恐龙存活的年代提早了几百万年。

These earliest dinosaur-like animals were about the size of domestic cats. They would have weighed two or three pounds (1 to 1.5 kilos) and walked on four legs.

But what's really intrigued scientists is that they date from two million years after the worst mass extinction event in the history of the planet.

It was a time when volcanic eruptions, sudden global warming and a stagnation of the oceans wiped out more than 90% of all life on Earth.

Up until recently scientists thought that dinosaurs emerged 15 to 20 million years after this event. But the new footprints suggest that they arose directly as a result of the devastation, filling a gaping ecological void. Without the mass extinctions there would have been no dinosaurs.

Glossary 词汇表

dinosaur 恐龙 

to be intrigued 被吸引，使好奇 

mass extinction 大量灭绝 

volcanic eruption 火山爆发 

global warming 全球变暖 

stagnation （海水）停滞 

to wipe out 毁灭 

footprints 脚印，足迹 

devastation 毁灭，破坏 

gaping 敞开很大的 

ecological 生态的 

void 空隙

Questions and Answers

True or false: The newly-discovered dinosaurs were much smaller than a cat. 

False. The dinosaurs were about the same size as a domestic cat.

True or false: Giant waves in the sea caused the mass extinction. 

False. The oceans were stagnant or motionless at this time.

True or false: Only 10% of life on earth survived the disaster. 

True. The disaster killed over 90% of life on earth.

True or false. The dinosaurs were affected by a severe drop in the planet's temperature. 

False. The planet was affected by global warming at the time.