阅读理解
We see humans all around us. But when was the first human seen? Early humans did not leave behind any written records. However, they left behind many paintings on the walls of the caves(洞穴) where they lived. These paintings tell about their life, and we know these early humans walked on four limbs(四肢) like apes (猿). Also, they did not live at one place but moved from place to place in search of food and water.
Without any tools, early humans used stones, bones of animals, and sharp pieces of wood to dig, hunt and cut their food. They also used these to protect themselves from animals. Since stones were used to make tools, this age was called Stone Age.
With time going, tools made of bones and stones were replaced with metal(金属的) ones which were stronger, sharper, and long-lasting. Metals were also used for farming and making knives. Copper(铜) was the first metal to be used.
The first fire that early humans noticed was natural fire caused by lightning(闪电). With fire, early humans could now light up dark caves. They could keep themselves warm during cold weather and cook meat. Also the fire could drive animals away.
Early humans noticed new trees growing from the seeds(种子) that fell to the ground from the fruits. This gave them the idea that they could make their own food by planting seeds, which led to farming. With the beginning of farming, early humans began to settle down(定居). They moved out of the caves and lived on farms and near their fields together, then the first villages came up.
Raising animals was a big event in human history that changed the life of early humans. The wild dogs were probably the first animal to be raised. As time went, goats, sheep, cows, donkeys, and horses were kept, too. This led to herding(畜牧业). Milk, meat and wool came from these animals.
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