The largest, most complex type of settlement in the urban hierarchy is the farm.
O suburb.
O megalopolis.
O city.
O hamlet.

The answer to this question is  c. pharmaceutical accumulation  reclaimed water refers to the water that being used again after it already  used for agricultural purposes.this type of water often contains pharmaceutical accumulation because of the chemical fertilizer that is used for the plants is absorbed into the water.

Well, a and b together would be negative. b alone would also be negative.

2pi more meters because you find the circumference which is 6pi and 4pi and subtract it and you get 2pi