Final Answer:
The two sentences that contain incorrect punctuation are:
1. "The American writer and philosopher, Henry David Thoreau comments that by simplifying one's life, 'the laws of the universe will appear less complex.'"
2. "The adrenaline produced in our body during a confrontation leads to two possible responses by the person: run away to safety, or stand one's ground and fight."
Step-by-step explanation:
1. In the first sentence, there is a comma before "Henry David Thoreau," which creates a comma splice. The correct punctuation should be: "The American writer and philosopher Henry David Thoreau comments that by simplifying one's life, 'the laws of the universe will appear less complex.'"
2. In the last sentence, a colon should be used after "person" to introduce the two possible responses. The corrected sentence reads: "The adrenaline produced in our body during a confrontation leads to two possible responses by the person: run away to safety, or stand one's ground and fight."
Correct punctuation enhances the clarity and readability of sentences, ensuring that the intended meaning is conveyed accurately.