65% of degradation is caused by too much animal grazing and treeclearance, constituting 35% and 30% respectively.
这句话来源于剑桥雅思考试真题8考官给的写作范本。图中显示35%的土地流失是由于过度放牧，30%是由于滥砍滥发。本句话“constituting...”的逻辑主语不应该是本句话的主语，也就是“65% ofdegradation”吗？可是目前非常显然应当对应的是“animal grazing and tree clearance”。难道是被动语态的用法，对分词作状语的逻辑主语还有影响？还是范本写错了？求解答！
65% of degradation is caused by too much animal grazing and tree clearance, constituting 35% and 30% respectively.
非常明显，constituting 35% and 30% respectively 的逻辑主语，是并列的 animal grazing and tree clearance。respectively 说明了问题。
用被动语态的目的，就是让逻辑主语animal grazing and tree clearance 与 constituting 35% and 30% respectively 紧挨着。