Which of the following is true about the grand coulee dam?

a. it is almost as tall as niagara falls.
b. it provides hydroelectric power.
c. it is the only naturally occurring dam in the columbia plateau.
d. it is the only dam on columbia river.

B. Grand Coulee Dam is the largest in the United States. The dam is higher than twice of the Niagara Falls. The Grand Cooley Dam on the Columbia River (Washington) was built to control floods, irrigate irrigation, provide hydroelectric energy and regulate the level of the river. The dam consists of concrete and at the expense of its weight withstands the pressure of water mass, ice. There are exist 14 dams on the Columbia River (3 in Canada and 11 in the United States).

porter is writing economic history because he is focusing on the cost of developing vaccines.

food chain i would say only because there is competition on getting food and survival