Section A

　　26. [E] challenges

　　27. [J] searched

　　28. [D] categorizing

　　29. [K] similarities

　　30. [L] slightly

　　31. [G] percentage

　　32. [O] traditional

　　33. [ I ] regardless

　　34. [H] proving

　　35. [M] suggests

　　Section B

　　36. [I]

　　37. [D]

　　38. [J]

　　39. [F]

　　40. [B]

　　41. [H]

　　42. [C]

　　43. [K]

　　44. [G]

　　45. [E]

　　Section C

　　passage one

　　46. [B] He intends to get rid of the tipping practice.

　　47. [C] It forces the customer to comensate the waiter.

　　48. [D] They can have some say in how much their servers earn.

　　49. [A] Services quality has little effect on tip size.

　　50. [D] Waiters should be paid by employers instead of customers.

　　passage two

　　51. [C] The impact of cheap oil on global economic growth.

　　52. [D] Consumers will spend their savings from cheap oil on other commodities.

　　53. [C] They use their money reserves to back up consumption.

　　54. [B] Its negative effects more than cancel out its positive effects.

　　55. [A] People are not spending all the money they save on gas.