The factory is being enlarged to make room for more machiner

这是一句现在进行时态＋被动语态的结构,局中“is being”构成进行时态,‘being enlarged’构成被动语态.‘is’和‘being’都是组动词,不是行为动词.只是在语法上帮助构成进行时态和被动语态.
例如：“The question is being asking to have more detail answer.”(问题正在被提问中,以取得更详细的回答.).