Systematic observation, measurements and experiment and the formulation .testing.and modification of hypothesis
Answer:
D. Oxygen
Explanation:
Oxygen is the most abundant element in the bodies of living things. For example, oxygen is about 65% of the human body.
Oxygen in the body is mostly in the form of water, since the bodies of living things need water to create energy needed every day.
Answer:
Oxygen debt is a physiological phenomenon in which a person consume oxygen at fater rate that it replaced by new oxygen molecules.
As shown in the graph, oxygen debt occurs just after the end of exercise because oxygen is consumed at faster rate during exercise that leads to increased respiration and body attempts to replace the used oxygen.
To overcome the problem of oxygen debt, a person should take rest that allows the body to replenish its oxygen supply.
Answer:
I believe the answer is C
Explanation:
Endoskeleton
A. Insects and crustaceans
B. Fish
C. Insects especially the pollinators
D. All vertebrates <span />