the coolest thing was the belt.改成疑问句应该怎么改

问题描述:

the coolest thing was the belt.改成疑问句应该怎么改
是 was the belt the coolest thing?还是 was the coolest thing the belt

应该是Was the coolest thing the belt?
按照语法,the coolest thing是主语.而the belt是表语.
变疑问句时不能把两者调换的.