Someone help me please

The large increase in atmospheric carbon dioxide in the last 50 years most likely comes from a. an increase in cellular respiration b. increased decomposition by bacteria c. an increase in the burning of fossil fuels d. an increase in photosynthesis

Asquirrel population lives in an area. over many years, a river in that area grows wider and stronger, eventually forming a canyon. the squirrel populations on the two sides of the canyon can no longer mate with each other and ultimately form distinct species. this is an example of

The mixture of sperm and fluids from the seminal vesicles, prostate gland, and cowper's glands is called