(Hardback)

Read and find out about how cities work in this colorfully illustrated nonfiction picture book.

Millions of people live in cities around the world, but have you ever wondered how cities work

(Hardback)

"Machines help make work easier, like when you need to lift something heavy or reach way up high. 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!"--Amazon.com.