Answer: D. Hypothesis B is more useful because it suggests a way to test the relationship between heart rate and caffeine intake.
Hypothesis A and B both are suggesting that caffeine intake is related to higher heart rate. But hypothesis B is proving it more certainly by suggesting the affects of caffeine intake on heart rate. As, heart rate of most people will be higher 30 minutes after they drink a cup of coffee is testifying the fact, that higher heart rate is related with caffeine intake.
Therefore, hypothesis B is more useful because it suggests a way to test the relationship between heart rate and caffeine intake.
Answer: It's C
Explanation: because They also do not have a brain, respiratory system, or circulatory system.
Answer:b) The air at high altitudes are less dense, so its harder to breathe.
Explanation:
AS altitude increases, the air pressure drops. This reduces the amount of gas molecules in the air so the air becomes less dense compared to air closer to sea level.
Have prominently segmented bodies...have jointed appendages
The continental drift affects living organisms in that it causes changes in climates which puts selective pressure on organisms, causes changes in habitats, including when large amounts of shallow marine habitat were lost in the formation of Pangea. Additionally continental drift may cause an increase or decrease in competition among different species and also it happens so slowly that it does not affect living organisms
