答案是：
✘ A sincerely apology
✓ A sincere apology

sincere 是「真誠的（形容詞）」sincerely 是「真誠地（副詞）」 題目這裡的「一個真誠的道歉」應該用形容詞，所以應該是 A sincere apology. 可以再看看下面的例句：
He has made a sincere apology for his mistake.
He must apologize sincerely for his mistake.

DooEnglish 英文表達課

☘	讓你不再詞窮
☘	搞清楚文法
☘	學習鞏固期讓你學完不會忘記

了解課程