The Sun is the star at the center of (1) ________ Solar System. It is a nearly perfect ball of hot plasma. The Sun has inspired us since ancient times...

The Sun is the star at the center of (1) ________ Solar System. It is a nearly perfect ball of hot plasma. The Sun has inspired us since ancient times. It’s central to mythology and religion of (2) __________ around the world. It keeps our planet warm enough for living things to grow. It gives us light so we can see. It is by far the most important (3) ________ of energy for life on Earth. It is about a hundred times as wide (4) ________ the Earth. If there were no sun, many things wouldn’t occur like photosynthesis or the presence of oxygen, which would have caused no existence of life.

Select the most appropriate option to fill in blank number 3.