7.聽下面一段獨白,回答第17至20小題 17.What did the host family do when the speaker arrived? A.They held a welcome party. B.They asked him to take a bath. C.They showed him around the house. 18.What surprised the speaker? A.No one gave him any food. B.The family was not friendly. C.They showed him everything. 19.Who is Steve? A.The speaker's teacher. B.The speaker's classmate. C.The son of the speaker's host. 20.What's the lesson for the speaker? A.East,west,home is the best. B.Always tell Americans what you want directly. C.Never stay with an American host family again.