必修二Unit 4 ANIMAL EXTINCTION动物灭绝
Many animals have disappeared during the long history of the earth. 从地球有史以来的这段漫长时期，许多动物都消失了。
The most famous of these animals are dinosaurs. 这些动物中最有名的是恐龙。
They lived on the earth tens of millions of years ago, long before humans came into being and their future seemed secure at that time. 千百万年前，恐龙就在地球上生活，比人类的出现要早得多。当时他们的前景好像也很安全。
There were many different kinds of dinosaur and a number of them used to live in China. 当时有许多不同种类的恐龙，其中有很多种类曾经生活在中国。
The eggs of twenty-five species have been found in Xixia County, Nanyang, Henan Province. 25个种类的恐龙蛋是在河南省南阳西峡县发现的。
Not long ago a rare new species of bird-like dinosaur was discovered in Chaoyang County, Liaoning Province. 不久前，在辽宁省的朝阳县新发现了一种罕见的、形状像鸟一样的恐龙。
When scientists inspected the bones, they were surprised to find that these dinosaurs could not only run like the others but also climb trees. 科学家们观察他们的头骨时，惊奇地发现他们不仅跟其他恐龙一样可以跑，而且还可以爬树。
They learned this from the way the bones were joined together.科学家是根据恐龙骨骼的连接方式得知的这些。
Dinosaurs died out suddenly about 65 million years ago. 恐龙大约在6500万年前就突然地灭绝了。
Some scientists think it came after an unexpected incident when a huge rock from space hit the earth and put too much dust into the air. 有些科学家认为恐龙灭绝是发生在一件意外事故之后，当时宇宙间一块巨石击中地球因而在空气中扬起太多的尘土。
Others think the earth got too hot for the dinosaurs to live on any more.另外一些科学家则认为，地球变得太热，因此恐龙无法在地球上生活了。
Nobody knows for sure why and how dinosaurs disappeared from the earth in such a short time. 没有人确切地知道恐龙是由于什么原因，又是怎样在这么短的时间里从地球上消失的。
We know many other wild plants, animals, insects and birds have died out more recently. 我们知道，近来许多其他的野生动植物、昆虫和鸟类也灭绝了。
According to a UN report, some 844 animals and plants have disappeared in the last 500 years. 根据联合国的一份报告，在过去500年里，有844种动植物消失。
The dodo is one of them. It lived on the Island of Mauritius and was a very friendly animal. 渡渡鸟就是其中的一种。它生活在毛里求斯岛上，是一种非常友好的动物。
Please listen to a story of the dodo and how it disappeared from the earth.请听一个关于渡渡鸟的故事，看看它是如何从地球上消失的。
