第5章因特网基础 【考点一】因特网的重要作用与构成 (一)因特网的重要作用 1丰富的信息资源2便利的通信服务3快捷的电子商务 (二)因特网的构成 1通信线路通信线路是因特网的基础设施,各种各样的通信线路将因特网中的路由器、计算机等连接起来,可以说没有通信线路就没有因特网。因特网中的通信线路归纳起来主要有两类:有线线路(如光缆、铜缆等)和无线线路(如卫星、无线电等)

CONTENTS Chapter One Chapter Two Chapter Three Chapter Four Chapter Five

Chapter Three Communications Channel Unit 10 Part 1 Notes to Text Part4 Extensive Reading Part 2 Word Study Part5 Notes to Passage Part3 Practice on Text Part6 Practice on Passage

Chapter Three Data Transfer in Digital Circuits Unit12 Part Notes to Text Part4 Extensive Reading Part 2 Word Study Part5 Notes to Passage Part3 Practice on Text Part6 Practice on Passage

Chapter Four Computer Software ordPercE x3 Unit14 Part 1 Notes to Text Part4 Extensive Reading

Chapter Four High-level Programming Languages e Part 1 Notes to Text m Part4 Extensive Reading o Part 2 Word Study Part5 Notes to Passage s Part3 Practice on Text Part6 Practice on Passage

Chapter Four Measures For Computer Security Firewall Antispyware Antivirus Antispam Unit 18 Part 1 Notes to Text

Part 1 Notes to Text Part4 Extensive Reading Part 2 Word Study Part5 Notes to Passage Part3 Practice on Text Part6 Practice on Passage

Chapter One Transition to Modern Information Science Unit3 Part 1 Notes to Text Part 2 Word Study Part5 Notes to Passage Part3 Practice on Text Part6 Practice on Passage Part4 Extensive Reading

Chapter Two Data Processing Unit 5 Part 1 Notes to Text Part 2 Word Study Part5 Notes to Passage Part3 Practice on Text Part6 Practice on Passage Part4 Extensive Reading