Best Wallpapers Hd News

Best Wallpapers Hd wallpapers


How it works

the solar system

A solar system is a group of planets and one or more stars. Our solar system has just one gigantic star, the Sun. It also has eight planets and three dwarf planets. Many planets have their own moons. There are also thousands of asteroids, meteoroids, and comets. Gravity from our huge Sun holds the sol... read more

people who study the earth

Throughout history, people have always wanted to understand the planet we live on. They wanted to know why the weather changes from hot to cold and back again. They wanted to know why it rains or snows and what lightning and thunder are. They wanted to know why volcanos erupt and why earthquakes move ... read more

ussr

Former nation extending from eastern Europe E across Siberia to the Pacific Ocean. In the N it bordered on the Arctic Ocean and in the S on China, and on southwestern Asian countries. The USSR, successor to the Russian Empire, was the world’s largest nation in area and was third in population. It co... read more

the human body organs and systems

Your body is like a complex machine. Many parts make up your body and work to keep you going. Some parts, like your eyes and hands, are easy to see. Some parts, like your vocal cords, hide inside your body. When you hum, the vibrations you feel are your vocal cords at work. Some parts of the body are ... read more

people learn from plants

Why Study Plants? ... read more