当不定式作find, think, feel, consider等动词的宾语，且有名词或形容词作宾语补足语时，必须使用it作其形式宾语，相当于其后所接的宾语从句。例如：

    Some students find it difficult to study English = Some students find (that) it is difficult to study English. 一些学生发现英语很难学。

    Bill Gates feels it his duty to help the poor = Bill Gates feels (that) it is his duty to help the poor. 比尔·盖茨觉得济贫是他的义务。

    I think / consider it wrong to do like that = I think / consider (that) it is wrong to do like that. 我认为那样做是错误的。

    注意：

    在“find / think / consider / feel 等 + it + n. / adj. + to do sth.”句型中，当宾语补足语是“no use或no good”时，“to do sth.”应改用“doing sth.”。例如：

    I think it no use fighting each other. 我认为彼此开战没什么用。