A parallel sentence mentions the same grammatical expression twice. I would go with "D". 'Passed' and 'Demonstrated' are both past tense words that express the same past tense grammatical idea.
If you have more questions, feel free to ask me.
When Huck's father shows up, I would presume
Good luck~~
Answer:
Depends on the situation
Explanation:
In the modern world evil is more common than many may think. Being good doesn’t come easy
I’m not sure but probably gold.
Answer:
Myelin is an insulating layer, or sheath that forms around nerves, including those in the brain and spinal cord. It is made up of protein and fatty substances. This myelin sheath allows electrical impulses to transmit quickly and efficiently along the nerve cells.