In which example does the author use classification? Clouds are first classified according to how they are formed. There are two basic types: (1) Clouds formed by rising air currents. These are piled up and puffy. They are called “cumulus,” which means piled up or accumulated. (2) Clouds formed when a layer of air is cooled below the saturation point without vertical movement. Many people exercise daily. Often, people choose activities such as running, cycling, or swimming. These aerobic exercises burn calories and keep the heart and lungs healthy. However, one disadvantage is that they don’t build muscle strength. Resistance training such as lifting weights can help, but it requires equipment. Harmful algae blooms occur when microscopic water plants called algae grow out of control and produce dangerous toxins. They can even make the air hard to breathe and turn the water red. That’s why the blooms are sometimes called a red tide. This book will look at homeschooling from two perspectives. It will show how homeschooling affects both teachers and students. I will show that there are both pros and cons to homeschooling.