【評論主題】751.Some experts offered a variety of scientific explanations for this natural _____.(A) phenomenon(

【評論內容】現象

【評論主題】三、有鑒於人工物料搬運作業不當易造成人員身體傷害，美國國家職業安全與衛生局（National Institute for Occupational Safety and Health, NIOSH）於

【評論內容】大反，小正，一固定