Fire was discovered many thousands of years ago.The first time humans saw fire was probably when a tree was destroyed by lighting(闪电).Humans soon learned how to make fire.They probably made the first fire by rubbing(摩擦)two sticks together.Fire was very important to humans.They needed to...
Presents information on research conducted on the Zhoukoudian cave, Beijing, China, which examined methods used by our ancestors to tame fires. When this epochal achievement possibly occurred; Reference to the book 'Homo erectus'; Importance of the mastery of fire to human development.EBSCO_Asp...
First you play the role of li yang fang and then the role of Susan you partner Mike has and Kim sun you are at the airport to meet you visitor you know each other so great you visit first talk with him and then take him to the hotel. Pledged to meet you representative someone answe...
A.when did he buy the carB.where did he buy the carC.when he bought the carD.where he bought the car 免费查看参考答案及解析 题目: When I was young, I always thought I had the meanest mother in the whole world. While other kids ate candy for breakfast, I had to have porridge,...
46 ( )to speak when the audience interrupted him. A.Hardly had he begun B.No sooner had he begun C.Not until he began D.Scarcely did he begin 免费查看参考答案及解析 题目: [选择题] 9 When a speaker express his intention of speaking ,such as asking a person to open the win...
You use your legs to push the pedals. Your energy is transferred (转移) to the bike. That makes the bike move. Now imagine riding your bike to create enough power to run a computer. Some students at one school did just that! They jumped on bikes connected to generators (发 电机) and...
Fire was very important to humans.They needed to keep warm at night.They used fire to cook food.(53)They used fire to keep enemies and wild animals away.In some parts of the world fire was used to send massages.The Indians in America,for example,used fire to make smoke as a message...
andtextileswilltheybegintousetheirlastplace—a landfilloutsidethecity. Theprogramisn?tthecity?sonlygreeninitiative (倡议 ).Ithasalready hadoneofCanadaandthe world?slargestsolarpanels,anditissaidthattheyare steadilyworkingtowardsashiftto100% renewable energy.Thecityalsohassubsidized (补助)farmers? marketsand...
Fire was very important to humans. They needed to keep warm at night. They used fire to cook food.Theyusedfiretokeepenemiesandwildanimalsaway.In some parts of the world fire was used to send messages. The Indians in America, for example, used fire to make smoke as a message. In some ...
They are able to make a smell map of their flying area. Some animals can sense the earth’s magnetic field (磁场), while humans can’t. This magnetic field guides a certain kind of fish when they swim a long way to a place and then back. How can this kind of fish do that? It ...