31 Because   of the large  number   of monitoring   and operating
stations   required   and the extensive   auxiliary   machinery,   a fairly
large  number   of ________   personnel   are needed  for operating
and maintenance.
(A) engine  room
(B) well-trained
(C) operation   space
(D) three  dimension

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統計： A(1), B(0), C(0), D(0), E(0) #3999797