To make the text more detailed and more intresting, to catch their attention
I think it's D because A is correct B could be right and C is wrong. But the answer D is basically A and B combined. I know i explained that horribly but D should be correct.
Answer: A) yesterday’s;
Explanation:
In this example, the right answer to use the semicolon. The semicolon is used to join two independent clauses that are really closely related in thought. This punctuation mark is between the full stop and comma.
In this example using the semicolon connected these two sentences without using the conjunction.
Answer:
1) A cardiovascular system is an organ system that conveys blood through vessels to and from all parts of the body, carrying nutrients and oxygen to tissues and removing carbon dioxide and other wastes.
2) "Capillaries connect the arteries to veins. The arteries deliver the oxygen-rich blood to the capillaries, where the actual exchange of oxygen and carbon dioxide occurs. The capillaries then deliver the waste-rich blood to the veins for transport back to the lungs and heart. Veins carry the blood back to the heart."
3) A heart attack is a blockage of blood flow to the heart muscle.
