"Explains to the reader how good it is to have libraries"--

For 5,000 years and more, libraries have been gathering and preserving writings of all kinds. They’re keepers of the world’s memory. They’re storehouses o

Simple machines are around us all the time and we use them every day. You might not even think of them as machines. Many are built into complex (compound) machi

A satellite is a small object travelling around something bigger. The Moon is a natural satellite of Earth. A spacecraft launched into orbit around Earth is an

We could not live without water. Almost two-thirds of our body weight is water. We rely on it to keep ourselves clean, to keep our bodies nourished, and to get