How do the massive colonies of zebras mussels cause problem

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.

According to new research, more than 5..5 million deaths are associated with polluted air. hope this : ).