D. J. Ward
Author
Accelerated Reader
IL: LG - BL: 3.7 - AR Pts: 1
Description
Machines are everywhere! They help make work easier, like when you need to lift something heavy or reach way up high. Some machines are so simple that you might not think of them as machines. There are six simple machines: the lever, the wheel and axle, the pulley, the ramp, the wedge, and the screw. Can you adjust a seesaw to lift an elephant? What happens when you combine two or more simple machines? Read and find out!
Author
Description
Millions of people live in cities around the world, but have you ever wondered how cities work? All those people need clean water to drink, a safe place to live, and a way to get all around the city! How do you take care of all those people's needs? Your city has a plan for that. Read and find out all about the systems a city has to help keep everyone safe, healthy, and happy.
This book on city systems will appeal to the young civil engineer. How...