i am not sure where i should have left it

问题描述:

i am not sure where i should have left it
这句话是什么从句?为什么sure后面可以直接跟一个句子

后面接的是宾语从句
形容词的宾语从句,常用来引导宾语从句的形容词有: sure,certain,glad,please,happy,sorry,afraid,satisfied,surprised