这句话的句型结构怎么分析啊?

问题描述:

这句话的句型结构怎么分析啊?
when the 18 to 24-year-group were asked in a study to nominate the "worst years of life",the teen years received more nominations than did any period except " over 70 years".

前面是一个从句,由when引导,即when sb is asked to do sth,后面是一个比较句 省略了theythe teen years received more nominations than THEY did any period except "over 70 years"最后的时间壮语是 any period ex...