Fill in the blanks. A___1_____,which often use p___2_____ language and a____3____ pictures, play an important p__4___ in our lives. There are two main t___5__ of advertisements.One is called c____6____ advertisements, which are m_____7___ to p___8___ a product or s __9__. But they don't tell c___10____ the c___11___ truth. Another one is called PSA, which are often placed for f__12__.They d__13__ with many social i__14__, which often affect public w___15___. (注意:答案写完整的单词,注意大小写。)