Each rung of the DNA ladder is made up of A( single nitrogen base
B( pair of nitrogen bases
C( pair of carbon bases
D( single carbon base

The picture represents a structure of the respiratory system. which is the function of this structure? to bring air into the body to exchange oxygen with carbon dioxide to carry air to the lungs to release oxygen from the body

Fill in the blank with the best word to complete the sentence. white blood cells protect against and aid in blood clotting when injuries are sustained.

Hydroelectric uses moving water to do work such as grinding grains in a mill true or false