我买了一个新手机，它运行速度很快。

I bought a new phone and ___it runs very fast.

很难完成这个任务，因为它需要太多时间。

___It is hard to finish this task because ___it takes too much time.

看来我们已经错过了末班车。

___It seems we've missed the last bus.

是他完成了这个项目，不是我。

___It was he who finished the project, not me.