Here are the best answers to your punctuation test.  Rule and page numbers correspond to your New Century Handbook.  Please look back at the rules that you missed, especially those rules that you violated several times.  Please ask me for any further clarifications.
 

1. The Braves have played well so far, and they hope to win the World Series this year.
RULE: 46.b (page 704)

2. Everyone’s grades have been calculated: there are nine A’s and twelve B’s in my 1102 class.
RULES: 27.a.4 (page 552); 27.b.4 (pages 555-556); 52.j (page 755); 48.b (page 720); and 49.c.1 (page 726)

3. The tall, attractive, young woman sat next to the window.
RULES: 46 d (page 705) and 46.c (page 705)

4. He hoped to be three-quarters finished by Friday; in fact, he gave us his word.
RULES: 54.c (page 766); 47.b (page 716); and 46.f (page 708)

5. A well-planned, thoughtful speech followed the video preview.
RULES: 46.d (page 705) and 54.b (page 765)

6. Shakespeare’s Hamlet questioned whether or not his life were worth living: “To be or not to be?  That is the question.”
RULES: 49.a (pages 724-725); 48.c (pages 720-721); 50.a (pages 728-729); 50.e (pages 731-732); and 45.e (page 698)  NOTE: Hamlet (the character), not the play, asks the question.

7. She used a month’s vacation to write her first series of children’s books.
RULE: 49.a (pages 723-724)

8. Computers, which were less common twenty years ago, now dominate our lives.
RULE: 46.e (pages 705-706)

9. The host was a well-known scientist and author: Carl Sagan.
                OR
9. The host was a well-known scientist and author, Carl Sagan.
RULES: 54.b (page 765) and 48.a (pages 719-720) or 24.c (page 516)

10. When we say that a country is “undeveloped,” we imply that it is backward in some way.
RULES: 50.a (pages 728-729); 50.b (pages 729-730); 50.e.1 (page 731); and 46.a (page 703)

11. Those new blue jeans look very well made and have a stylish, up-to-date cut.
RULES: 54.b (page 765) and 46.d (page 705)

12. Bran contains large amounts of fiber; nutritionists recommend adding it to our diets.
RULE: 47.a (page 715-716)

13. I loved Scarlett O’Hara when she said “Tomorrow is another day” at the end of Gone With the Wind.
RULES: 49.b (page 725); 50.e.5 (page 732); 52.e (page 753); and 45.d.4 (page 697)

14. Tuesday, April 22, 1986, was the day we first kissed.
RULE: 46.g.1 (page 708)

15. Ireland is a country divided: Northern Ireland is mostly Protestant; the rest of Ireland is mostly Catholic.
RULES: 48.b (page 720) and 47.a (pages 715-716)

16. John Keats’ poem “Ode on a Grecian Urn” depicts two lovers frozen in time before they kiss.
RULES: 47.a (pages 723-724) and 50.d (pages 730-731)

17. Arnold Simpson, Sr., PhD, lectured in Greek drama.
RULES: 46.g.3 (page 709); 45.b (page 696); and 53.a (page 758)

18. My guidance counselor said, “I think you should take calculus next year”; I disagreed.
RULES: 46.h (pages 709-710); 47.a (pages 715-716); 50.a (pages 728-729); and 50.e.2 (page 731)

19. Sinbad, the comedian, has little in common with his namesake, the main character from A Thousand and One Nights.
RULES: 46.e (pages 705-706); 24.c (page 516); and 52.e (page 753)

20. Her main job responsibilities – as she later found out – were not as exciting to her as she first thought.
RULES: 51.a (page 736); 51.d (pages 738-739); and 51.e (page 739)

21. Dogs have a greater sense of smell than humans have; therefore, they are valuable in criminal investigations.
RULES: 47.b (page 7160 and 46.f (page 708)

22. Honestly, I have never heard of that before, have you?
RULES: 46.a (page 703) and 46.i (page 710)

23. Ruben had final exams scheduled on Monday, December 10; Tuesday, December 11; and Wednesday, December 12.
RULE: 47.c (page 716)

24. My girlfriend stepped into the ladies’ room while I used the “little boys’ room.”
RULES: 49.a (pages 723-724) and 50.b (pages 729-730)

25. Bill Gates, the all-powerful, self-made millionaire, could purchase several island nations with his immense wealth.
RULES: 46.e (pages 705-706); 24.c (page 516); and 54.b (page 765)