Why do you think there are so many places to visit along the nile river?

Because the Nile River is an tourist attraction and where there's people there's stores.

The answer to the first one is barometer.

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.