I not only want to do well on this test, but I also need to do well on this test.
The correct answer is parenthesis. A parenthesis normally appears in sentences when extra information unrelated to the main idea of the sentence is inserted. The trick in knowing if a phrase can be included in a parenthesis is when you take it out and the idea of the sentence is intact.
I would say the correct answer is - <span>But the doctor's four friends had taught no such lesson to themselves. They resolved forthwith to make a pilgrimage to Florida, and quaff at morning, noon, and night, from the Fountain of Youth.
As you already said, allegory is something that tells us a deeper and more important story than what may seem on the surface. So these four people don't just want to go on a pilgrimage and find the Fountain of Youth on a whim - there must be something important behind their decision.
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