Researches show that most ulcers develop because of the infection with a bacterium called Helicobacter pylori---also referred to as H.pylori.
一、结构：
主语—Researches
谓语动词—show
宾语从句—that most ulcers develop 多数溃疡逐步形成
原因状语—because of the infection with a bacterium called Helicobacter pylori — also referred to as H.Pylori 由于由于受到一种叫做幽门螺杆菌的细菌——也可以称其为幽门螺杆菌的细菌——的传染
二、语言点解释：
1—the infection with a bacterium called Helicobacter pylori：这个called Helicobacter pylori 作名词 bacterium 的后置定语,相当于定语从句 a bacterium which is called Helicobacter pylori,意思是“叫做幽门螺杆菌的细菌”
2—过去分词短语 referred to as 是由主动形式 refer to sth.as 化来的,意思是“称某物为…”,在此处是对破折号前同样形式的 called Helicobacter pylori 的进一步说明,相当于 which is referred to 意思是“被称作…的（细菌）”
3—most：adj.作“大多数”解释,没问题.
4—because of the infection with a bacterium called Helicobacter pylori：改为：由于受到一种叫做螺杆菌幽门的细菌传染.
修正翻译：研究表明大多数溃疡的形成是由于受到一种叫做螺杆菌幽门的细菌——也可以称其为幽门螺杆菌的细菌——的传染.
