56. ________ you decide to take up, you should try to make it a success.
A) Whatever B) Unless C) Whenever D) If only

57. Most parents encourage their children to take an active part in social events, ________ those events do not interfere with their studies.
A) lest B) though C) unless D) provided

58. What ______ would happen if the director knew you felt that way?
A) do you suppose B) you suppose C) will you suppose D) you would suppose

59. No sooner had we reached the top of the hill ________ we all sat down to rest.
A) when B) then C) than D) until

60. Evidence came up ________ specific speech sounds are recognized by babies as young as 6 months old.
A) what B) which C) that D) whose

61. The situation today is obviously quite different from ________ it was only 50 years ago.
A) what B) which C) when D) such

62. Most doctors recognize that medicine is ________.
A) an art as much it is a science B) as much an art as it is a science
C) as an art as much it is science D) much an art as it is a science

63. ________ the punishment was unjust, Helen accepted it without complaint.
A) However B) So long as C) Even though D) Since

64. The time has come ________ we can make extensive use of nuclear energy.
A) when B) while C) as D) since

65. Some metals are better conductors of electricity than others , _____ means that the former have atom that contain more free electron than the latter.
A) that B) this C) which D) it
有一些金属比其他金属相比则是更优良的电流的导体，这也就意为着，前者比后者具有更多的自由电子

66. There is hardly an environment on earth ________ some species of animal or other has not adapted to an environment successfully.
A) to which B) wherever C) so that D) as to

67. ________ we have finished the course, we shall start doing more revision work.
A) For now B) Now that C) Ever since D) By now

68. The goals for _______ he had fought all his life no long