D is the answer to the problem
Hunting, I believe. Hope this helped
X-rays were discovered by accident (by Wilhelm Rontgen).
Answer:
Carbon dioxide, Oxygen
Explanation:
The circulatory system of our body works following two pathways -
In pulmonary pathway the deoxygenated blood is carried to the lungs while in the second pathway, known as systemic pathway, the oxygenated blood is carried to the various parts and organs of our body. Thus the completed sentence in the question will be -
Blood being pumped by the heart is circulated in two circuits. One circuit carries blood with high levels of carbon dioxide to the lungs, and the other circuit carries blood with high levels of oxygen to the body.
Answer:
The correct answer would be adaptive radiation.
It is a natural phenomenon by which ancestor species diversify into new forms as a result of adaptation towards changing the environment, limited or different resources, new challenges or new ecological niches.
For example, Darwin's finches faced new niches, different environment, different types of food resources due to which they adapt to different species bearing beaks of different shapes and sizes.