It's an area of land that is covered with snow or water from rain or snow
Answer:
Places around Cairo and Aswan are the largest concentrations of people in the region.
Explanation:
Concentration means how spread out things are in space. They could either be clustered or dispered. The purple on this map represents clustered, and as you can see, that Cairo is the largest city and the capital of Egypt, which is one reason why it has the largest concentrations of people.
Not sure if you still need it but the answer is (c) new cities were built along the shores of the Great Lakes.
