61. Output is now six times ________ it was before 1990.

　　A) that B) what

　　C) for which D) of that

　　62. The heavily populated area was a breeding place for ________ diseases.

　　A) infectious B) powerful

　　C) influential D) suspicious

　　63. It is unfortunate that, owing to lack of money, these experiments must now be ________ before the objective has been achieved.

　　A) transferred B) testified

　　C) terminated D) transformed

　　64. The synthetic vitamins are identical ________ those naturally present in our food.

　　A) for B) of C) as D) with

　　65. Just as a book is often judged ________ by the quality and appearance of its cover, a person is judged immediately by his appearance.

　　A) previously B) uniquely C) outwardly D) initially

　　66. Recycling wastes slows down the rate ________ which we use up the Earth’s finite resources.

　　A) In B) of C) with D) at

　　67. Gasoline is ________ by the spark plugs in the engine.

　　A) ignited B) inspired C) excited D) illuminated

　　68. He ________ another career but, at the time, he didn’t have enough money to attend graduate school.

　　A) might have chosen B) might choose

　　C) had to choose D) must have chosen

　　69. Many visitors praised the magnificent architecture of the Palace, ________.

　　A) known to foreigners for the Forbidden City

　　B) known for foreigners to be the Forbidden City

　　C) known to foreigners as the Forbidden City

　　D) know for foreigners as the Forbidden City

　　70. The travelers ________ their journey after a short break.

　　A) recovered B) resumed C) renewed D) restored

　　61. B 62. A 63. C 64. D 65. C

　　66. D 67. A 68. A 69. C 70. B