wh does the life on earth depend on sun

This is because the sun is the source of almost all the energies in our earth. Plants make food using sunlight, the food that we get from plants and animals also has its prime source as sunlight. The fossil fuels that we use in our daily life comes from dead plants and animals which again have their source as solar energy. The wind that blows is due to the heat absorbed by the atmosphere from the sunlight.