38 If the work involves the use of oil, precautions for preventing ________ accidents are necessary.
(A) fire
(B) sinking
(C) falling
(D) flooding
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統計: A(38), B(15), C(3), D(10), E(0) #3255934
統計: A(38), B(15), C(3), D(10), E(0) #3255934