求分析下句语法结构,特别是后半句reversing……to 18的语法结构
问题描述：
求分析下句语法结构,特别是后半句reversing……to 18的语法结构
Twenty states have rasised the legal drinking age to 21,reversing a trend in the 1960s to reduse it to 18.
答
主语：Twenty states 二十个州
谓语动词：have raised 已经提高
宾语：the legal drinking age to 21 法定饮酒年龄到21岁,
伴随状语：reversing a trend in the 1960s to reduse it to 18 （与此同时）改变了六十年代把它降低到18岁的倾向
注：分词短语可以用作时间、原因、条件和伴随方式状语,本句中的现在分词短语reversing a trend …就是伴随方式状语.这个句子也可以改写如下：
Twenty states have rasised the legal drinking age to 21 and reversed a trend in the 1960s to reduse it to 18. 【并列句】
Twenty states have rasised the legal drinking age to 21 while they have reversed a trend in the 1960s to reduse it to 18 . 【复合句】
参考译文：二十个州已经把法定饮酒年龄提高到21岁,这一举措改变了六十年代将其降低到18岁的倾向.