1.  It is a fact that…

　　2.  It is well-known that…

　　3.  There is no doubt that…

　　4.  I think that…

　　5.  Contrary to the popular thought，I prefer…

　　6.  Some people say/believe/claim that…

　　7.  It is generally believed that…

　　8.  It is widely accepted that…

　　9.  It is argued/held that…

　　10.  While it is commonly believed that…， I believe…

　　11.  It can be concluded that…

　　12.  People‘s views vary from person to person.