This book contains 22 true-or-false questions about rocks and minerals; readers may read the question on the right and turn the page to see the answer on the left.
Explains the cycle of evaporation, condensation, and precipitation that provides fresh water to the earth and describes how this supply is brought to people's homes.
Explains the cycle of evaporation, condensation, and precipitation that provides fresh water to the earth and describes how this supply is brought to people's homes.
Discusses a variety of robots, real and imaginary, with or without human form, which perform some humanlike functions--seeing, hearing, thinking, speaking, etc.