Lesson One 1
Text:The Scientist and the Willow TreeGrammar：一般过去时Reading Material:The Food FactoryLesson Two 14
Text:The EcosystemGrammar：Ⅰ．一般将来时 Ⅱ．情态动词Reading Material:Changing EnvironmentLesson Three 29
Text:A Letter to a FriendGrammar：Ⅰ．现在完成时 Ⅱ．动词的四种基本形式Reading Material:Life at the UniversityLesson Four 44
Text:What Is a Number?Grammar：形容词和副词的级Reading Material:The Decimal System and the Binary SystemLesson Five 58
Text:Exploring the Ocean DepthsGrammar：数词Reading Material:Skin-divingLesson Six 71
Text:Scale the Heights of ScienceReading Material:Let's Race Against TimeLesson Seven 83
Text:Oil and GasGrammar：被动语态（—）Reading Material:Wealth from the GroundLesson Eight 96
Text:The MoonGrammar：Ⅰ．被动语态（二） Ⅱ．宾语补足语和主语补足语Reading Material:Our GalaxyLesson Nine 109
Text:Relay Stations in SpaceGrammar：动词不定式（一）Reading Material:Radio Waves from SpaceLesson Ten 122
Text:EarthquakesGrammar：动词不定式（二）Reading Material:VolcanoesLesson Eleven 135
Text:ComputersGrammar：Ⅰ．句子类型 Ⅱ．状语从句（一）Reading Material:How a Computer"Reads"InformationLesson Twelve 150
Text:Mathematics Arose out of the Needs of MenReading Material:The Right-angled Triangle TestSupplementary Readings 164
1．Hibernation2．Some Concepts in Biology3．The Uses of Oxygen4．The Uses of Mathematics5．The Deepest Parts of the Oceans6．The National Science Conference7．Locating Positions on the Earth8．The Universe9．Space Travel10．Inside the Earth11．How a Computer Works12．From Squares to Other FiguresAppendix Ⅰ 187
A List of Common Irregular VerbsAppendix Ⅱ 193
Common Grammatical TermsAppendix Ⅲ 198