The main idea is basically it is informing you that animals are simply in the hospital to help patients.
The answer is D because the commas are in the correct places
Punishment and sometimes faliure
The correct answer is C: The rich have too much time on their hands and not enough to think about. Pope tries to punctuate the ridiculousness of a society in which values have lost all proportion and the society the poem describes is one that isn't able to distinguish between what really matters and what doesn't. His intention was to cool hot tempers and to encourage people to laugh at their own absurdity.
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