例句：I found it astonishing that he should be so rude to you.他竟然對妳這樣無禮，真讓我吃驚。
What have I done that you should be so angry with me?我做了什麽,妳竟然會這樣對我生氣?
這是個what引導的特殊疑問句，語序倒裝，所以用have I done,而後面的that又引導了壹個定語從句,用陳述語序。should在定語從句中是情態動詞，加強語氣，表“竟然”。