pardon

下面四句都不对：

• I am sorry, for I have not answered your letter.
• Excuse me, for I have not answered your letter.
• Forgive me, for I have not answered your letter.
• Pardon me, for I have spoken rudely.

该改作：

• I am sorry that I have not answered your letter.
• Excuse me for not having answered your letter.
• Forgive me for not having answered your letter.
• Pardon me for having spoken rudely（或speaking rudely）.