for they greedily devoured what was left of the cake .这句话what是什么用法,翻译

问题描述:

for they greedily devoured what was left of the cake .这句话what是什么用法,翻译

因为他们贪婪地吃光了仅剩的蛋糕.
what在此处引导宾格的宾语从句.