当宾语从句后跟有宾语补足语时，通常在宾语从句处使用形式宾语it，而将真正的宾语从句移至句末：
I think it best that you should stay here. 我认为你最好住这儿。
He hasn’t made it known when he is going to get married. 他还没宣布他何时结婚。
She found it difficult to answer the question. 她发现回答这个问题很困难。
He feels it his duty to hetp others. 他认为帮助别人是他的责任。
He thought it best to be on his guard. 他认为他最好还是要警惕。
He made it a rule to speak in Parliament at least once every session. 他规定自己在议会每次开会时至少发一次言。
I find it interesting talking go you. 我觉得同你谈话很有意思。
I consider it wrong to cheat in an examination. 我认为考试作弊是不对的。