在讨论开始前，老师设定了几条基本规则以确保每个人都有发言机会。

Before the discussion started, the teacher set some basic ___ground-rules to ensure everyone gets a chance to speak.

由于球场较小，裁判制定了特殊的场地规则限制击球距离。

Due to the small field, the referee set special ___ground-rules to limit hitting distance.