Dinosaurs(恐龙) lived millions of years ago, a long time before people. There are no dinosaurs alive today, so nobody has ever seen a living dinosaur.

In the days of the dinosaurs, the world was a very different place from today. The weather was warmer and the land with forests of strange-looking trees and plants was everywhere. There were no animals such as horses or sheep.

Some dinosaurs were the hugest animals that have ever lived on land(补充语法分析). Most of them were not at all intelligent(聪明的). Even the hugest dinosaurs only had small brains(脑).

Some dinosaurs only ate plants. These were often heavy, slow-moving dinosaurs. Many of them spent much of their time in water because the water helped to hold them up. It also helped to hide them. Other dinosaurs were meat-eaters. These dinosaurs had sharp(锋利的) claws and teeth for catching, holding and tearing(撕碎) food.

恐龙生活于数亿年前，远早于人类。今天已经没有恐龙活着，所以从未有人见过活的恐龙。

在恐龙时代，世界与今天截然不同。气候更加温暖，奇形怪状的树木与植物构成的森林无处不在。这里几乎没有马或羊之类的动物。

有些恐龙是有史以来在陆地上生活过得最大的动物，他们大多一点也不聪明。事实上，这些最大的恐龙只有很小的大脑。

有些恐龙只吃植物，他们通常是笨重而行动缓慢的恐龙。他们中的很多，大多时间在水中度过。因为水可以帮助他们支撑起硕大的身躯，也可以帮助他们隐藏自己。其他恐龙是肉食动物，这些恐龙有锋利的爪子和牙齿用来捕获、抓稳并撕碎食物。