The Hertz sprung-Russell Diagram shows the three vert different types of stars. The first type is called the Main Sequence which includes the sun. These stars are fueled by nuclear fusion, converting hydrogen into helium. The hotter they are, the brighter they become. They last for about five billion years. The second type includes super giants. As they reach old age, they deplete their hydrogen supply. Their core contracts as their outer layers expand. Eventually, they will explode becoming nebula or supernova, then white dwarfs, neutron stars, or black holes. Third, smaller stars consequently become white dwarfs, shrinking and depleting their nuclear fuels, finally becoming cold, dark black dwarfs. A.classification text B.enumeration text C.time order text D.explanatin text (TEXT TYPE ACCORDING TO PURPOSE AND FEATURE
