Which statement correctly describes an interaction between two body systems that regulate internal conditions in an animal's body? A: Signals carried by nerve cells cause an increase in the heart rate.
B: Hormones released by neurons enter the bloodstream.
C: Hemoglobin enables red blood cells to carry oxygen molecules.
D: New red blood cells form from division of cells in the bone marrow,​

currents is the correct answer.

4.) metal

"-the movement of carbon from the nonliving environment into living things and back to the environment

-carbon is the essential component of proteins, fats, and carbohydrates (which make up all organisms)

-carbon exists in air, water, and living organisms

-producers convert carbon dioxide in the atmosphere into carbohydrates during photosynthesis

-bacteria in the atmosphere cycles through the system in filtration units

-in cellular respiration, carbon is released back into the atmosphere as carbon dioxide

-some carbon is stored in limestone (forming one of the largest "carbon sinks" on earth)

-largest carbon reservoir on earth= limestone

-carbon stored in the bodies of organisms as fat, oils, or other molecules may be released into the soil or air when the organism dies

-this may form deposits of coal, oil, or natural gas (fossil fuels, which increased the atmospheric carbon dioxide)

-fossil fuels store carbon left over from bodies of organisms that died millions of years ago

-they are located in the surface of earth, deep within the earth and beneath the ocean floor."    

we need additional information in order to determine the cause of death for anna garcia. there are at least 3 things with explanation included as to why we need them are as follows: