knock sb. down with a feather

• v. 使人十分惊奇

knock sb. down with a feather的用法和样例：

例句

用作动词 (v.)

1. If we had seen the Wiltons enter the ballroom,we could have knocked us down with a feather.
   如果我们看见威尔登夫妇进入舞厅，我们会十分惊奇。