8. Which of the following is an example of a positive feedback mechanism? O A. During childbirth, the baby's head pushing on the cervix encourages uterine contractions.
O B. The kidneys retain more water if the organism's water level is low.
O C. Body temperature is increased if skeletal muscles move quickly and cause a person to shiver.
O D. Insulin causes cells to absorb glucose

the element that provides strength to the exoskeletons of clams and oysters is phosphorus.

this is so because calcium carbonate is the main component in the shells. calcium carbonate is strengthened by phosphorus.

explanation:

paper covers rock.

explanation:

rock only smashes scissors.

propane is burned to provide the heat in many cooking grills. the chemical reaction for this process is shown in the equation below.

c3h8 + 5o2 ? 3 co2 + 4h2o + energy

what are the products in this chemical reaction?

3co2 + 4h2o + energy