Listen to a radio program on compliments in American English. Complete the answers to the following questions according to what you hear. What are the common structures Americans use to compliment each other? (a) What a ...! (e.g. "What a nice hat!") (b) I like your ... (e.g. "I like your hat.") / I love your ... (e.g. "I love your shoes.") When is it appropriate to compliment people in the United States? (a) When they have done something well. (b) When we like _________.(答案为四个英文单词).