Unit 1 Water Cycle
Text A：Hydrologic Cycle
Text B：Water's Journey Through Time
Unit 2 Water Resources
Text A：Facts on Water Resources
Text B：Types of Water Resources
Unit 3 Lakes and Rivers
Text A：Freshwater Lakes and Rivers
Text B：Rivers， Streams， and Creeks
Unit 4 Reservoirs
Text A：Types of Reservoirs
Text B：Three Gorges Reservoir Region
Unit 5 Flood Control
Text A：Flood Control and Disaster Management
Text B：More Floods， More Effective Flood-fighting Technology
Unit 6 Irrigation and Drainage
Text A：Modern Irrigation System Planning and Construction
Text B：Modern Drainage System Construction
Unit 7 Dams
Text A：Dams Are a Vital Part of the National Infrastructure
Text B：Dams： What They Are and What They Do
Unit 8 Hydraulic Turbines
Text A：Hydro Turbine
Text B：Factors Affecting the Selection of Hydraulic Turbines
Unit 9 Hydroelectric Power
Text A：Hydropower Today
Text B：Hydroelectric Energy and Its Pros and Cons
Unit 10 Water Pollution
Text A：Water Pollution-Everything You Need to Know
Text B：What Are the Effects of Water Pollution?
Appendix：Glossary
