【正文】
rcial ads PSAs purpose expense believable? examples to promote a product or service to educate people charged free of charge no yes ①② ①②③④ mercials Advertisements PSAs promote charged tricks examples educate free of charge believable radio, TV…, images, language Reading strategy: reading expository writing (說明文) introduction of subject supporting details conclusion a subject Homework: 1. Finish the article on Page 95. 2. List the difficult language points on your notebook. 3. Retell the article about advertisement .