it是什麼意思呢

It is estimated the project will last four years.

據估計，這項工程將持續四年。

She found it extremely difficult to get a job.

她發覺找工作極其困難。

We estimated it would cost about  5 000.

我們估計要花費大約5000歐元。

It's almost time to go.

是差不多該走的時候了。

There is some doubt about the best way to do it.

這件事怎麼做才是最佳辦法有點吃不準。