object lesson
practical illustration of some principle, often given or used as a warning 实际教训
Let this accident be an object lesson in the dangers of drinking and driving. 这一事故可以作为醉酒驾驶危害的实际教训.
Undivided attention is another sign of respect. You may have noticed that very few people listen with complete attention. Most people half-listen, and if you ask them to repeat what you have just said, they cannot. They may appear to be listening, but i