49. In the passage above, the studies of economists suggest that _____.
(A) crop yields and natural temperature should not be linked together
(B) too much temperature increase suppresses crop yields
(C) 30 degrees Celsius is the threshold for the growth of soybeans
(D) with more scorching days crop yield increase could be expected
(E) France and China suffer from temperature increases

45. According to the passage, the word episodic means ______. (A) constant (B) periodic (C) suicidal (D) uncontrollable (E) self-conscious

46. Which of the following statements best represents the main idea of this passage? (A) Fossil fuels could offer enormous benefit. (B) Carbon dioxide helps bump crop yields. (C) Carbon dioxide affects climate change. (D) Climate change and crop yields are closely related. (E) Carbon dioxide effect could help chillier regions to produce more crops.

47. According to the passage above, which of the following statements is TRUE? (A) Humans might have raised the level of carbon dioxide by 40% in this century. (B) All life runs on fossil fuels. (C) Some plants convert carbon into glucose. (D) Extra gas could always supercharge food crops. (E) Plant growth depends more on fossil fuels than on gas.

48. Scientists in the above passage suggest that _____. (A) the use of fertilizers could affect level of carbon dioxide (B) plant growth is dependent on climate change (C) spraying extra carbon dioxide helps plant growth (D) crops are very sensitive to heat (E) to bump crop yields we need more researches 第 5 頁，共 6 頁

50. What is implied by the phrase our best guess at the moment in the last paragraph of the passage above? (A) Climate change was aided by the carbon dioxide effect. (B) Climate change was likely to pose severe challenges for agriculture in the tropics. (C) Climate change aided by the carbon dioxide effect is probably beneficial in some of the chillier regions of the Northern Hemisphere. (D) Climate change reduces the dependence on fossil fuels. (E) Economists are no equal to scientists in terms of climate change.

51. With what will the "purists" want their jello to be made? (A) Chopped fruit and nuts. (B) Ice cream. (C) Chopped mint leaves. (D) Orange whip. (E) None of the above.

52. What does the speaker in the above passage want to convince the reader to do? (A) Eat more jello. (B) Realize that jello is well-liked by everyone. (C) Serve jello in many different ways. (D) Prepare jello in ordinary ways. (E) Know all the above.

53. To whom is the above passage most likely addressed? (A) Restaurant chefs. (B) Children who like desserts. (C) The family cook (mom especially). (D) Readers reading the recipes. (E) None of the above.

54. According to the passage above, which of the following is NOT the thing people would do to spend their Sunday morning? (A) Playing ball. (B) Watching people passing below. (C) Gazing at the sky. (D) Leaning on the sills and watching aimlessly. (E) Looking at the streets disinterestedly.

55. In Line 5, what is the meaning of the sentence “they had already taken up their posts?” (A) They had already gathered the mails sent to them. (B) They had already taken their positions to fight. (C) They had already started the jobs. (D) They had already started doing this. (E) They had already accepted the positions.