letter of regret

• 致歉信

letter of regret的用法和样例：

例句

1. The parents then complained about the incident and were sent a letter by the school saying the teacher has been disciplined over the gaffe.
   随后家长们向校方投诉了这件事，校方得知后给每位家长发了致歉信，称这位老师出言不慎，已受到处分。