The correct answer to this open question is the following.
The land on the banks of the Nile differed from the rest of the land in Egypt because the banks benefited from the flooding of the Nile River, making the soil very fertile to grow crops. Egypt is a desert. The weather conditions are extreme. That is why the Nile is called the lifeblood of Egypt because Egyptians depend on the water of the river to survive, to grow crops, to bathing, and for transportation.