Much to the couple’s comfort ,their income is now double what it was five years ago.what it was five years ago式表语从句还是宾语从句?now double做什么成分?double是adv.还是vt.

Much to the couple’s comfort ,their income is now double what it was five years ago.
what it was five years ago式表语从句还是宾语从句?
now double做什么成分?
double是adv.还是vt.

宾语从句
double表语
double是adj