Sun-A very important source

Sun is a very important part for all the living creatures in this world, if there were no sun no creature could have existed, plants grow due to the sun's light, they absorb sunlight and make their food panel absorbs sunlight and generates electricity etc,It provides warmth, illumination and by attracting and at the same time keeping all planets rotating around it, thus producing night and day.Rays of light when reaches our skin, it produces vitamin D2, which is vital to our bones.It is also one of the main ingredients for plants to provide oxygen for us.When the goes out, everything will die within a week. This is because the plants cannot perform the process of photosynthesis.As plants give out oxygen as a by-product which we take in, if they will die, naturally even we will die.Not only that but we can also die due to starvation because plants will not be able to produce any food for us.Without the sun our whole earth would be freezing and we all will die.Therefore, keeping all the points in mind, we can say that 
"SUN IS THE ULTIMATE SOURCE OF ENERGY ON EARTH!!!"