object lesson

1. N-COUNT If you describe an action, event, or situation as an object lesson, you think that it demonstrates the correct way to do something, or that it demonstrates the truth of a particular principle. (作教訓或原理的)實例[oft N 'on/in' n]

It was an object lesson in how to use television as a means of persuasion. 這是利用電眡作爲勸導方式的一個實例。