How can using a dam as a source of freshwater also harm agricultural resources?

The dam acts as a barrier between upstream and downstream.  Dams are also built for irrigation, but it is also deliberately destroyed in favor of irrigated farming. Though it provides freshwater, and makes people be protected by droughts, but it can also damage the agricultural resources by limiting the water in some areas. 

Dams can collect topsoil during floods.

white blood cells or wbc s are mainly 2 types-

1.agranulocytes

2.granulocytes

the monocytes or macrophages of agranulocytes , dendritic cells which are accessory leucocytes, and b cells which is one type of lymphocytes   identify the antigens present on the pathogen's surface. these three cells are called antigen presenting cells(apc) which are phagocytes and destroy the antigens by secreting antitoxins. besides this leukocyte is always plays vital role in the immunity of the body.

the answer is b)3/8x+1