To be fair, this observation is also frequently made of Canada and Canadians, and shouldbest be considered North American.
【译文】 公平地讲,经常有人也这么说加拿大和加拿大人,因此这种现象最好被看作是一种北美现象。
【析句】 To be fair作全句的状语,主语是this observation,主语有两个谓语,一个是系动词is,一个是should best be considered。