51．
A．know
B．have known
C．need know
D．need to know
52．
A．With
B．in
C．on
D．at
53．
A．diet
B．meals
C．food
D．dinner
54．
A．use
B．devote
C．spend
D．take
55．
A．on
B．in
C．with
D．about
56．
A．if
B．whether
C．either
D．neither
57．
A．To complete
B．Completing
C．Completion
D．To be completed
58．
A．as
B．for
C．on
D．about
59．
A．Unless
B．Once
C．If
D．Although
60．
A．around
B．with
C．about
D．on
61．
A．work
B．task
C．job
D．place
62．
A．on
B．with
C．after
D．by
63．
A．thought
B．idea
C．thinking
D．talk
64．
A．for
B．in
C．with
D．On
65．
A．reap
B．harvest
C．benefit
D．1ead