Which best explains why water quality standards have been created to ensure heavy metals in water are kept to a minimum? O A. Heavy metals are linked to toxicities in humans and large amounts of heavy metals should not be consumed.
OB. Heavy metals can stain ceramic surfaces in homes and cost the homeowners hundreds in repairs.
OC. Heavy metals can cause discoloration of water and can cause a strong unpleasant odor.
O D. Heavy metals can corrode pipes and cause problems with internal plumbing.

Which of the following describes a negative feedback loop? when the heart rate is too high, the body sends hormones that continually increase the heart rate higher. when a pregnant woman is in labor, the body sends hormones that increase the intensity of contractions, which then increases the secretion of the same hormones. when blood sugar is too low, the body sends hormones that raise blood sugar until it reaches a typical level and hormone secretion slows. when a person is jogging, the body sends hormones that continually decrease the rate of oxygen supply to the legs.

Which of the follow describes a disadvantage secondary sources have compared to primary sources?

Modern sea star larvae resemble some primitive vertebrate larvae. this similarity may suggest that primitive vertebrates