Much of the world's population lives in modern cities. A lot of planning is required to accommodate all of these people and provide the services they need. Inside Modern Cities looks at all of the infrastructure a modern city needs to thrive, from wastewater treatment systems to mass transit. Learn how architects, scientists, and engineers work together to make these cities work. Core Library is the must-have line of nonfiction books for supporting the Common Core State Standards for grades 3-6. Core Library Features: A wide variety of high-interest topics, Well-researched, clearly written informational text, Primary sources worn accompanying questions, Multiple prompts and activities for writing, reading, and critical thinking Charts, graphs, diagrams, timelines, and maps, Visit abdocorelibrary.com for free additional tools for teachers and students.