I'm terribly sorry — I'm terribly sorry for the wait.
I apologize — I apologize for the trouble.
I'm really sorry — I'm really sorry about this.
试一试: Amina: There is a problem with my room. Hiroshi: ___ What is wrong? Hiroshi works at the hotel and wants to apologize. Which fits? (I'm terribly sorry. / Excuse me, but / I'm not happy with) 答案: I'm terribly sorry. — I'm terribly sorry 是一句道歉，正好对应 Hiroshi 的回答。Excuse me, but 和 I'm not happy with 都是用来抱怨的，都不是在道歉。
礼貌地抱怨
想礼貌地抱怨，先说 Excuse me, but，然后在说明问题之前用 There's a problem with 或 I'm not happy with。
Excuse me, but — Excuse me, but this is cold.
There's a problem with — There's a problem with my room.
I'm not happy with — I'm not happy with the noise.
试一试: Sofia: How is everything in your room? Diego: ___ the noise. I can't sleep. Diego wants to complain politely about the noise. Which fits? (I'm not happy with / I apologize / I'm really sorry) 答案: I'm not happy with — I'm not happy with 引出一句礼貌的抱怨，正合适。I apologize 和 I'm really sorry 都是道歉，都不是在抱怨。