it後面加動詞的第三人稱單數形式、過去式、原形等。
it：pron.(指提到過的或正在談論的動物或事物)它指嬰兒，尤指性別不詳者指已知或正在發生的事實或情況。 擴展資料
It is estimated the project will last four years.
據估計，這項工程將持續四年。
It was not a propitious time to start a new business.
那不是營業開張的吉時佳日。
She found it extremely difficult to get a job.
她發覺找工作極其困難。
It would be preferable to employ two people， not one.
僱請兩個人比僱請一個更好。
We estimated it would cost about 5 000.
我們估計要花費大約5000歐元
