Many adults may think they are getting enough shut-eye,but in a major sleep study almost 80 percent of respondents admitted to not getting their prescribed amount of nightly rest. 请问老师这个句子的成分分析？以及study后面是不是省略了什么？

     【答】but 是并列连词，连接两个句子。在前一个句子中，Many adults 是主语，may think 是谓语动词，划线部分是宾语从句，作 may think 的宾语。在后一个句子中，in a major sleep study 是状语， almost 80 percent of respondents 是主语，admitted to 是谓语动词， not getting their prescribed amount of nightly rest 是否定形式的动名词短语作介词 to 的宾语。study 是名词，意思是“研究”，它后面后面没有省略的内容。