31. According to the passage, what makes Pop Rocks a notable candy in the US?
(A) Its affordability and long shelf life.
(B) Its variations in recipes.
(C) Its unique packaging.
(D) Its distinct eating experience.

27.(A) coordinates(B) stimulates(C) pursues(D) manufactures

28.(A) medical(B) recreational(C) physical(D) dietary

29.(A) proposed(B) revealed(C) termed(D) defined

30.(A) Excessive(B) Moderate(C) Average(D) Conventional

32. What misconception about Pop Rocks is mentioned in the article?(A) They are too sweet and often cause tooth decay.(B) Consuming them with soda leads to stomach explosions.(C) They contain harmful chemicals used in science experiment.(D) Baking soda and vinegar are two of their main ingredients.

33. Why did General Foods temporarily withdraw Pop Rocks from shelves?(A) Because of the legendary death of a celebrity.(B) To create a new and improved version.(C) Due to declining sales compared to other drinks and desserts.(D) To replace it with a healthier candy alternative.

34. What does the article say about the recipes inspired by Pop Rocks?(A) They are all of high quality.(B) They are only suitable for drinks.(C) They are used for different creations.(D) They are primarily used by experienced chefs.

35. Which of the following words is closest in meaning to the word "relish" in the last paragraph?(A) convert(B) savor(C) enhance(D) conquer

1. Derivatization reactions are often used in preparation samples for chromatographic separation, which of the following statements are not the major purposes of these reaction?(A) Increasing the detection sensitivity.(B) Increasing separation resolution for chiral compounds.(C) Increasing the application range of chromatographic analysis.(D) Decreasing the analytes reaction with the separation column.(E) Decreasing the retention time of analytes.

2. Which of the following gas chromatographic detectors are nondestructive types?(A) Flame ionization detector.(B) Flame photometric detector.(C) Thermo-conductance detector.(D) Nitrogen phosphor detector.(E) Mass spectrometry detector.