《21世纪大学英语》（S版）系列教材（第3版）根据国家教育部颁发的《大学英语教学指南》（2020版）和《中国英语能力等级量表》以及我国高等院校人才培养特点和教学改革的最新成果编写而成，突出教育必须立德树人的时代要求，重视教学内容的实用性和针对性，在帮助学生培养正确的世界观、人生观和价值观的同时，将语言基础能力的培养与实际涉外交际能力的训练有机地结合起来，以满足新时代社会经济发展对大学生的要求。
本系列核心教材包括《综合教程》《综合练习》《教学参考书》（每一种分为1—4册）及配套的MP3、微课、助教PPT课件、“i学”App移动平台网络课程、超星“学习通”App示范教学包等。本套教材供高等院校普通英语教学使用。
本书为《教学参考书》第1册，共8个单元，每个单元根据《综合教程》的相关内容配备教法推荐、作者介绍、背景知识、课文详解以及练习答案和录音文本等。同时，本书在版式设计上力求易用（User-friendly），将学生用书的内容完整地融入教学参考书，课文讲解采用“左学右教”的方式，以方便教师教学。本书另配有PPT助教课件。

Unit 1 Freshmen
I.Objectives
II.Suggested Teaching Plan
III.Background Information
IV.Class Presentation
Part I Lead-in
Part II Listening
Part III Reading
Text A: College Survival: Our Tips for Success
Text B: My College Move
Part IV Speaking
Part V Translation & Writing (Registration Forms)
Part VI Critical Thinking
Part VII Time to Relax
Unit 2 AI
I.Objectives
II.Suggested Teaching Plan
III.Background Information
IV.Class Presentation
Part I Lead-in
Part II Listening
PartIII Reading
Text A: The Internet of Things
Text B: Big Data Is Everywhere
Part IV Speaking
Part V Translation & Writing (Application Forms)
Part VI Critical Thinking
Part VII Time to Relax
Unit 3 Mobile Technology
I.Objectives
II.Suggested Teaching Plan
III.Background Information
IV.Class Presentation
Part I Lead-in
Part II Listening
Part III Reading
Text A: The Negative Effects of Cell Phones
Text B: Mobile App Designer
Part IV Speaking
Part V Translation & Writing (Business Name Cards)
Part VI Critical Thinking
Part VII Time to Relax
Unit 4 Faith
I.Objectives
II.Suggested Teaching Plan
III.Background Information
IV.Class Presentation
Part I Lead-in
Part II Listening
Part III Reading
Text A: Who to Believe?
Text B: Tina's Ten Points
Part IV Speaking
Part V Translation & Writing (Greeting Cards)
Part VI Critical Thinking
Part VII Time to Relax
Unit 5 Exploration 22s
I.Objectives
II.Suggested Teaching Plan
III.Background Information
IV.Class Presentation
Part I Lead-in
Part II Listening
Part III Reading
Text A: Magellan's Madness
Text B: Marco Polo 's Big, Big World
Part IV Speaking
Part V Translation & Writing (Thank-you Notes)
Part VI Critical Thinking
Part VII Time to Relax
Unit 6 English as a Universal Language
I.Objectives
II.Suggested Teaching Plan
III.Background Information
IV.Class Presentation
Part I Lead-in
Part II Listening
Part III Reading
Text A: The Advantages of Learning English
Text B: Do You Know Tom Cruise?
Part IV Speaking
Part V Translation & Writing (Invitation Letters)
Part VI Critical Thinking
Part VII Time to Relax
Unit 7 Success
I.Objectives
II.Suggested Teaching Plan
III.Background Information
IV.Class Presentation
Part I Lead-in
Part II Listening
Part III Reading
Text A: Three Keys to Success
Text B: Consider This
Part IV Speaking
Part V Translation & Writing (Replies to Invitation Letters)
Part VI Critical Thinking
Part VII Time to Relax
Unit 8 Economics
I.Objectives
II.Suggested Teaching Plan
III.Background Information
IV.Class Presentation
Part I Lead-in
Part II Listening
Part III Reading
Text A: Economics
Text B: Double Your DOLLARS AND CENTS
Part IV Speaking
Part V Translation & Writing (Notices)
Part VI Critical Thinking
Part VII Time to Relax
Grammar Review
I.Countable and Uncountable Nouns
II.Adjectives and Adverbs: the Comparative Degree and the Superlative Degree
III.Modal Verbs
IV.Verb Tenses (1)
V.Verb Tenses (2)
VI.Verb Tenses (3)
VII.Passive Voice