Piedra de toque

"This photo-illustrated book for early readers describes the wetland ecosystem. Includes picture glossary and index"--

The early nineteenth century in the United States was a study of contrasts. On the one hand, the Jazz Age brought cultural liberation, vivacity, and reckless consumption; on the other, the Great Depression brought poverty and desperation to millions. Explore these periods in American history through the eyes of the people who lived them.

What causes sound? How does sound travel? Sound begins when matter vibrates. Without this vibration sound could not move and nothing would make any noise. Starting with tiny molecules, this book explains the main concepts of sound and furthers understanding through a series of easy-to-do experiments that will appeal to readers of all ages.

The moon people, Kaluma, Aluma, and others use a cloud bridge to travel to the Earth, a messy but beautiful world of incredible variety that becomes their new home.