I always get confused about how to puncuate a sentence that ends with an abbreviation.
For example: "We will have dinner at 8 p.m.(.)" Is there a need for a period or does the second period in p.m. act as the puncuation?
Same goes for "Do you work at the U.N.?" Is this over-puncuating?
This is a little similar to our class discussion about how to puncuate the sentence "Do you Yahoo!?"