been是什么时态的

　　It's been quite a day, one way and another.

　　从几方面看，这是不寻常的一天。

　　Their family has always been well thought of around here.

　　他们家在这一带一直颇受敬重。

　　There have been many changes in recent years.

　　近几年发生了许多变化。

　　A new system has been devised to control traffic in the city.

　　控制城市交通的新系统已经设计出来。

　　We had to work within the parameters that had already been established.

　　我们必须在已设定的范围内工作。