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.