Passage A The brain is the boss of the body. Your eyes, ears, nose, and skin tell your brain what is going on around you. Other parts of your body tell your brain what is going on inside of you. Your brain takes in the signals. It tells your body what to do with them. When you touch fire, your skin tells your brain that your finger is too hot. Your brain tells you to move your finger. All these happen very fast. Your brain also controls your breathing, blinking, and heartbeat. It controls your feelings and thoughts too. Humans have the most developed brain of all animals. Yet it is not the largest brain. The human brain weighs three pounds. The brain of an elephant weighs 11 pounds. So the largest brain is not always the best brain. In people, a larger brain does not mean a clever person.