Can someone with this question?

7. how did the early egyptians use the flooding of the nile river to their advantage? they diverted the water to flood their enemy's lands and destroy their crops. they created an easier way to travel to the mediterranean sea and the indian ocean. they established a new water-based athletic event for the ancient olympics in greece. they devised an innovative irrigation system, which created a surplus of food.

Which of the following was a typical tactic of nativists in the late 1900?

Why would the free rider problem prevent a private business from investing in the building of a city sidewalk?