1)It’s well known to us that ...
2)As is known to us，...
3)This is a topic that is being widely talked about.
4)From the graph(table，chart)listed above，it can be seen that ...
5)As aproverb says，“Where there is a will，there is a way.
As is well known to us，it is important for the students to know the world outside campus.
The reason for this is obvious.Nowadays，the society is changing and developing rapidly，and the campus is no longer an“ivory tower .As college students，we must get in touch with the world outside the campus.Only in this way can we adapt ourselves to the society quickly after we graduate.
再如： Does it pay to be honest?This is a topic that is being widely talked about and different people have different opinions on it.