It is customary to ask others to pass dishes to you for self-serving; at a formal dinner party, there is usually catering ( service). 习惯上可以请别人将菜传给你自己来盛;在正式晚宴上则通常会有分菜(服务)。
It is customary for the young men to draw lots for military service in this country. 在这个国家里年轻人必须抽签决定去服兵役是一种习俗。