Sarah is testing different types of planting soil to determine which type is most effective in growing blueberry bushes. she purchases two different brands of planting soil from a local store. sarah applies brand a to 1 area of the yard and brand b to another area of the yard, both of which receive full sunlight. she waters the area with brand b daily; she waters the area with brand a every other day. at the end of the study, sarah concludes brand b is more effective in growing blueberry bushes. why is her conclusion not valid

Melting glaciers is a serious threat to the environment what is the possible consequence of melting glaciers on polar bears?

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 following can be reduced by the use of renewable energy sources? a. social costs b. economic costs c. environmental costs d. all of the above select the best answer from the choices provided a b c d