已知某商品的需求价格弹性系数为0.5，当价格为每公斤3.2元时，销售量为1000公斤。若价格下降10%，销售量是多少？该商品降价后，总收益是增加了还是减少了？增加或减少了多少？
参考答案
参考解析
【分析题】
患者，男，18岁，学生 。
主诉：上前牙外伤后牙齿变短半小时 。
现病史 ：半小时前骑自行车部不慎摔倒，面部嘴唇先着地，发现牙齿变短，但不松动 。
既往史 ：否认全身系统性疾病、传染病及其他特殊病史及药物过敏史 。
检查：11、21牙龈红肿，龈沟渗血，牙冠完整，内倾，但比邻牙短2mm，牙冠完整，叩痛(++)，松动(±)(图4-14-6) 。中切牙开
。上唇黏膜红肿，约有1cm长的裂口，渗血 。X线片示：11、21根尖周膜间隙消失，未见根折线（图4-14-7） 。38、48低位垂直阻生，龈瓣红，水肿，覆盖咬合面远中，盲袋无分泌物 。
1．主诉疾病的诊断、诊断依据和鉴别诊断 。
2．非主诉疾病的诊断和诊断依据 。
3．主诉疾病的治疗原则 。
4．全口其他疾病的治疗设计 。
主诉：上前牙外伤后牙齿变短半小时 。
现病史 ：半小时前骑自行车部不慎摔倒，面部嘴唇先着地，发现牙齿变短，但不松动 。
既往史 ：否认全身系统性疾病、传染病及其他特殊病史及药物过敏史 。
检查：11、21牙龈红肿，龈沟渗血，牙冠完整，内倾，但比邻牙短2mm，牙冠完整，叩痛(++)，松动(±)(图4-14-6) 。中切牙开
。上唇黏膜红肿，约有1cm长的裂口，渗血 。X线片示：11、21根尖周膜间隙消失，未见根折线（图4-14-7） 。38、48低位垂直阻生，龈瓣红，水肿，覆盖咬合面远中，盲袋无分泌物 。1．主诉疾病的诊断、诊断依据和鉴别诊断 。
2．非主诉疾病的诊断和诊断依据 。
3．主诉疾病的治疗原则 。
4．全口其他疾病的治疗设计 。
【分析题】
设计任务：请阅读下面学生信息和语言素材，设计20分钟的英语阅读教学方案。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：某城镇普通高中二年级（第一学期）学生，班级人数40人，多数学生已经达到《普通高中英语课程标准（实验）》七级水平。学生课堂参与积极性一般。
语言素材：
Business Motorola set out a special training plan programme for children last week with the aim of developing children's business skills and preparing them for a future as entrepreneurs.
Eighty-seven children aged between 12 and 16 from Beijing and Tianjin attended the one-week training programme called Youth Discovery directed by Motorola University's(MU) instructors and marketing specialists. The children learned about dealing with a practical problem-marketing and worked out a marketing plan by themselves. Last week 26 children of Motorola employees in Tianjin completed their training in the MU-Tianjin Learning Center.
Through the training programme, children learnt how to get information through different kinds of sources, determine end-user needs, make up messages of value to customers, and communicate using various means and equipment.
Educators acted only as team directors, providing children to discover their own answers. The children gave their solutions to Motorola's management and their parents on the last day of the programme.
The children, most of whom were primary and middle school students, presented themselves freely. The students said that they preferred the open and practical way of learning.
Youth Discovery, started by Motorola's former president Robert Galvin, designed and carried out by Motorola University, aimed to bring the talents of young people into full play and encouraged them to discover how their skills can contribute to a team to help it reach an aim.
