How did the formation of the ozone layer contribute to the existence of life on Earth? It blocked the Sun’s harmful UV rays. It caused water vapor to cool, condense, and collect. It released large amounts of oxygen into the air. It warmed Earth’s surface, preventing materials from freezing.

The answer is c, i, iii, and iv. this is because farming and mining deal with harvesting raw materials, construction work falls under manufacturing, and piloting a plane is a service. ii is wrong because making bread is using  raw materials to produce goods, which would fall under the secondary sector, not primary.