A celestial body consisting of a mass of gas held together by its own gravity in which the energy is generated by nuclear reactions in its interior. 1.Planet
2.Galaxy
3.Star
4.Moon

Answer (d) the greenhouse effect is primarily caused by car and trucks;

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.