There are a few requirements that unite all of these spirits while also distinguishing them from Western drinks, chiefly that baijiu is produced in a process known as solid-state fermentation.这里的chiefly that是做什么成分,是原因状语吗?谢谢。
个人觉得有两种可行的理解,如有不正确的地方欢迎指出。 第一种就是你所说的原因状语,放在这里是说得通的。 第二种是引导名词性从句,对前面的requirements中的一个加以诠释。前面提到了a few requirements ,表示有多个要求,而这下面的这个chiefly和that之间省略了the requirement,用于解释说明众多要求中主要的一个。连起来的表达就是,There are a few requirements that..., chiefly the requirement that... (注意这两个that的用法是不一样的)