Which will most likely alter the pH of rain? A. burning fossil fuels
B. using hydroelectric plants
C. using nuclear power plants
D. creating ethanol from biomass

Veins have a much lower blood pressure than arteries. which of these prevents backflow of blood in veins? a. pressure applied by the heart b. one–way valves in veins c. thin muscular walls of veins

Each nephron is made up of capillaries that form the __ sweat glands bladder glomerulus ureter

Which enzyme is responsible for “unzipping" the dna by breaking the hydrogen bonds between the nucleotides?