考研英语长难句宾补。

...benefits is to the release of oxytocin...主谓结构，故而宾补

宾补中宾语和补语之间有密切的联系，但通常由谓语造成了补语，attribute...to...，课件to后的the release of oxytocin是跟attribute（谓语）有着密切的关联，所以可以to the release of oxytocin做the stress-reducing, health-related benefits of hugging的宾补。换言之，其实是因为attribute这个谓语使得to the release of oxytocin作为的宾补。