51.
A. off
B. on
C. at
D. of
52.
A. is
B. was
C. were
D. are
53.
A. can
B. have to
C. need to
D. should
54.
A. after
B. for
C. in
D. at
55.
A. the
B. /
C. a
D. an
56.
A. With
B. If
C. But
D. And
57.
A. helping
B. being
C. get
D. be
58.
A. whose
B. who
C. that
D. when
59.
A. life
B. cars
C. warning
D. problem
60.
A. about
B. to
C. by
D. on
61.
A. use
B. inform
C. ask
D. teach
62.
A. let
B. allow
C. make
D. give
63.
A. have helped
B. helped
C. had helped
D. was helped
64.
A. speak
B. have
C. link
D. put
65.
A. lawyer
B. doctor
C. customer
D. specialist