Oneofthereasonsthataregivenfor....isthat....
______________的原因之一是__________________。
Perhapsthisisbecauseofthesimplefactthat.....
也许，原因很简单，亦即_____________________。
Oneofthepremiercausesisthat(注意用词)
最重要的原因之一便是______________。
Attheriskofsoundingtoosimplistic,itseemstomethatthemainpropositionscanbesummarizedinonesaying.
这个原因可能较简单，不过，我认为可以用一句谚语来概括，________。
Wemaylookintoeverypossiblereason,however,foremostreasonfor....Is....
其实有很多原因，不过，造成________的最重要的原因是______________。
Itmightalsobenotedthat....
Anotherreasonwhy.....(凑字数，但不可滥用)isthat....(有利于写长句)
Whatisalsoworthnoticingisthat....
值得一提的是___________________。
Thereisanotherfactorthatdeservessomewordshere.
Amoreessentialfactorwhy....Isthat
________的更为重要的原因是____________。
Afurtherreasonwhy,,,,isthat.....
________的更深层次的原因是____________。
Movingontowiderthemes,_______
展开来说，_________________________。
Thesecondthingthatmustbetakenintoconsiderationisthat...
