1 To ensure safety, workers must _______ all the rules in dangerous environments at all times.
(A) observe
(B) avoid
(C) twist
(D) impress
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統計: A(52), B(17), C(5), D(13), E(0) #3866849
統計: A(52), B(17), C(5), D(13), E(0) #3866849