am is are是谓语动词吗

　　Am I right in thinking that you used to live here?

　　我想你过去在这里住过，对吗？

　　I really and truly am in love this time.

　　我这一次确确实实是恋爱了。

　　The system was state of the art.

　　这一系统是当时最先进的。

　　In our company, quality is high on the agenda.

　　我们公司高度重视质量。

　　We are still friends, though, which is good.

　　不过我们仍然是朋友，这令人感到欣慰。

　　There have been many changes in recent years.

　　近几年发生了许多变化。