(before) a big crowd; (on) a public occasion

• 大庭广众

(before) a big crowd; (on) a public occasion的用法和样例：

例句

1. She said she had never spoken before an audience.
   她说她从未在大庭广众演讲过。
2. Mind your manners on a public occasion.
   大庭广众之下要注意礼貌。