根据提供的信息和语言素材设计教学方案。用英文作答。
设计任务：请阅读下面学生信息和语言素材，设计20分钟的英语听说教学方案。教案没有固定格式，但须包含下列要点：
 teaching objectives
 teaching contents
 key and difficult points
 major steps and time allocation
 activities and justifications
教学时间：20分钟
学生概况：某城镇普通中学初中一年级学生，班级人数40人。多数学生已经达到《义务教育英语课程标准(2011年版)》二级水平。学生课堂参与积极性一般。
语言素材：
Bob: Hi, Carol, How was your school trip yesterday?
Carol: It was great!
Bob: Did you go to the zoo?
Carol: No, I didn′t． I went to a farm． Look, here are my photos．
Bob: Did you see any cows?
Carol: Yes, I did． I saw quite a lot．
Bob: Did you ride a horse?
Carol: No, I didn ′t． But I milked a cow．
Bob: Did you feed any chickens?
Carol: Well, I saw some chickens but I didn′t feed them．
Bob: What else did you do?
Carol: My friends and I went for a walk around the farm and talked with a farmer．