This document discusses the key characteristics of living things. It lists seven characteristics that most living things have in common: 1) movement, 2) use of energy, 3) growth and development, 4) response to the environment, 5) reproduction, 6) homeostasis, and 7) being made of cells. It also explains that organisms are made up of elements like hydrogen, oxygen, carbon, and nitrogen, which form compounds. The most common compounds found in organisms are carbohydrates, lipids, proteins, and nucleic acids.