51. His understanding made a deep impression ________ the young girl.
A) in
B) on
C) for
D) to(D)
52. Silver is the best conductor of electricity, copper ________ it closely.
A) followed
B) to follow
C) following
D) being following(A)
53. There is hardly an environment on earth ________ some species of animal or other has not adapted successfully.
A) as to
B) wherever
C) so that
D) to which(C)
54. It is highly desirable that a new president ________ to this college.
A) appointed
B) be appointed
C) was appointed
D) has been appointed(B)
55. After searching for half an hour she realized that her glasses ________ on the table all the time.
A) were lain
B) had been lain
C) had been lying
D) would have been lying(C)
56. The time has come ________ we can make extensive use of nuclear energy.
A) when
B) while
C) as
D) since(D)
57. Hardly ________ the helicopter ________ when the waiting crowd ran toward it.
A) has ... landed
B) had ... landed
C) would ... land
D) was ... landing(A)
58. Although the weather was very bad the buses still ran on ________.
A) list
B) schedule
C) plan
D) arrangement(A)
59. The situation today is obviously quite different from ________ it was only 50 years ago.
A) such
B) which
C) when
D) what(D)
60. Jane was hit on the head by the robber and was knocked ________.
A) mindless
B) unconscious
C) brainless
D) unaware(B)