Listening Part 8: Summarize Spoken Text
PTE Listening Part 8- Sample 7: Summarize The Spoken Text
Formed approximately 4.6 million years ago, the sun is the star which is at the center of the solar system. Heated upto incandescence by nuclear fusion, it is a sphere of hot plasma which is also the most important source of energy on earth. Surprisingly, around three-fourths of the mass of the sun is hydrogen, where about a quarter is helium with almost negligible proportions of carbon, oxygen, neon and iron. Around 100 times the diameter of the earth, the sun is also known as the red giant that fuses millions of tons of hydrogen into helium every second which in turn converts around 4 million tons of matter into energy. As per certain research it has been found that the sun would engulf the orbits of Mercury and Venus, as well as it would also make the earth inhabitable, but that is likely to happen only 5 billion years later. Once this happens, the sun would shed its outer layer and become a dense type of cooling star known as a white dwarf which would no longer emit energy through fusion, but would light and release heat due to its previous fusion.