Dinosaurs once lived happily on the earth. But 65 __1__ years ago, they suddenly all died out. What happened __2__ them? Scientists think that a change in temperature may tell us why. They have come up with __3__ ideas to explain the end of the dinosaurs. The most famous one is the minor planet（小行星）idea. Let's go back to that day to see what happened. Everything was OK before a minor planet suddenly hit the earth. __4__ terrible hit! It __5__ big fires, storms, acid rain（酸雨）and even earthquakes（地震）and volcanic eruptions（火山爆发）. The hit made a lot of dust. It flew up into the air and kept the sun away for months. The earth became very cold __6__ sunlight. The __7__ died first. Then the grass-eating animals died because they had __8__ food. Then the meat-eating animals couldn't find food, __9__. They began to eat each other, but after a while they died out, __10__.

阅读理解

　　Firstly, what were dinosaurs?

　　Dinosaurs lived on Earth a long time age; some dinosaurs were huge and had long tails-they were bigger than a whole family of elephants. Others were very small-they were about the size of a chicken. Not all dinosaurs ate meat. Some just ate plants. Not all of them were dangerous. Some were harmless.

　　When did they live on earth?

　　Dinosaurs lived on Earth for about 135 million years. Man has lived here for only 35,000 years About 65 million years ago, however, all the dinosaurs died in a very short period of time. Nobody knows why it happened suddenly.

　　How do we know about dinosaurs?

　　Scientists study dinosaur bones and eggs to get information. They discover how dinosaurs lived, what they looked like, where they lived and what they ate. Scientists now believe that dinosaurs were very colorful animals.

　　Were they clever animals?

　　In the past, scientists thought that dinosaurs were slow and stupid. We now know that many dinosaurs were fast and powerful. Some were not only fast, but clever too. They used the long claws on their feet to kill their food. Other dinosaurs were probably very stupid. One very large dinosaur had a brain the size of a peanut!

　　Do you think they could ever live on Earth again?

　　In the Hollywood film Jurassic Park, a scientist brings dinosaurs back to life from an old egg. Scientists in China recently found some dinosaur eggs similar to the one in the film. Could they bring dinosaurs back to life? It is unlikely, but in science, anything seems possible!

根据文章内容填空

　　Dinosaurs used to live on Earth a long time ago. Some of them were 1 and others were very small. Some of them ate 2 and others ate plants. So not all of them are 3 .

　　They lived on Earth for about 4 million years. Nowadays scientists study dinosaur 5 and eggs to get 6 . Scientists used to think dinosaurs were 7 and 8 . But now we know that many of them were 9 and 10 .