案例：事件3:施工单位编制的大体积混凝土施工方案部分内容如下：
（1）水平施工缝采用风砂枪打毛处理。纵缝表面不作处理;
（2）夏季混凝土温控采取了降低混凝土出机口温度和浇筑后温度控制措施；
（3）坝体混凝土应在终凝后开始养护，养护时间不少于28d。
事件4：某坝段浇筑完成后，验收时发现了一条冷缝，需进行处理。
问题：
1.改正事件3中大体积混凝土施工方案的不妥之处。
2.事件3中，降低混凝土出机口温度和浇筑后温度控制措施的具体温控方法分期有哪些？
3.指出事件4中冷缝产生的原因和处理措施。
设计任务：请阅读下面学生信息和语言素材，设计一节20分钟的英语阅读课的教案。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：某城镇普通中学高中一年级（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）》六级水平。学生课堂参与积极性一般。
语言素材：
Who am I?
Over time I have been changed quite a lot. I began as a calculating machine in France in 1642.
Although I was young I could simplify difficult sums.I developed very slowly and it took nearly two hundred years before I was built as an analytical machine by Charles Babbage. After I was programmed by an operator who used cards with holes,I could "think"logically and produce an answer quicker than any person. At that time, it was considered a technological revolution and the start of my "artificial intelligence". In 1936 my real father, Alan Turing, wrote a book about how I could be made to work as a"universal machine"to solve any difficult mathematical problem. From then on, I grew rapidly both in size and in brainpower. By the 1940s I had grown as large as a room, and I wondered if I would grow any larger. However, this reality also worried my designers. As time went by, I was made smaller. First as a PC(personal computer) and then as a laptop, I have been used in offices and homes since the 1970s.
These changes only became possible as my memory improved. First it was stored in tubes, then on transistors and later on very small chips. As a result, I totally changed my shape. As I have grown older I have also grown smaller. Over time my memory has developed so much that, like an elephant, I never forget anything I have been told! And my memory became so large that even I couldn't believe it! But I was always so lonely standing there by myself, until in the early 1960s they gave me a family connected by a network. I was able to share my knowledge with others through the World Wide Web.
Since the 1970s many new applications have been found for me. I have become very important in communication, finance and trade. I have also been put into robots and used to make mobile phones as well as help with medical operations. I have even been put into space rockets and sent to explore the Moon and Mars. Anyhow, my goal is to provide humans with a life of high quality. I am now truly filled with happiness that I am a devoted friend and helper of the human race!
在不考虑资本流动和汇率变动的情况下，某经济的情况由以下方程和数据描述：
消费函数：c＝40＋0.8y；
进口函数：m＝30＋0.2y；
投资：i＝25；
政府购买：g＝25；
出口：x＝100。
求：（1）该经济均衡时的产出水平和相应的贸易收支。
（2）使贸易收支平衡的产出水平。
