通过对本单元的学习，能够运用本单元的知识去解决一些科学问题，并能在此基础上提出自己的见解。

Section Ⅰ-Warming Up，Prereading，Reading & Comprehending

　　一、将单词或短语与相对应的释义搭配起来

　　A　　　　　　　　　　B

　　1．theory　　　 a．different from；not similar to

　　2．unlike　　　 b．to be present or happen

　　3．prevent...from c．an idea or opinion

　　4．exist d．causing harm

　　5．harmful e．to stop/keep...from

　　二、短语互译

　　A．温故：从文中找出下列短语并写出它们的汉语意思。

　　1．according to　____________

　　2．cool down　____________

　　3．be different from　____________

　　4．depend on　____________

　　B．知新：从文中找出与下列释义对应的英文。

　　1．及时；终于　____________

　　2．阻止；制止　____________

　　3．下蛋　____________

　　4．产生；分娩　____________

　　5．轮到某人；接着　____________

　　三、阅读课文HOW LIFE BEGAN ON THE EARTH，按照地球的形成与发展，给下面的句子排序

　　(　　)A　Insects and amphibians appeared.

　　(　　)B　The earth was a solid globe.

　　(　　)C　Reptiles appeared.

　　(　　)D　The earth was just a cloud of dust.

　　(　　)E　Shellfish and all sorts of fish appeared.

　　(　　)F　Dinosaurs appeared.

　　(　　)G　Small plants began to grow on the surface of the water.

　　(　　)H　Plants began to grow on land.

　　(　　)I　Water began to appear on the earth.

　　(　　)J　Mammals (including humans)appeared.

　　四、阅读HOW LIFE BEGAN ON THE EARTH，回答下列问题

　　1．How were stars and other bodies created?

　　A．Atoms combined to create them.

　　B．Clouds of dust combined to create them.

　　C．Water combined to create them.

　　D．Gases combined to create them.

2．Which is the most important for life appearing on the earth?