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Conversation 1[听力原文]6-8M: When in Rome, do as the Romans do, they say.W: What do the Romans doM: They live in Rome, of course, and go to work by car or bus. But sometimes it takes too long that way because of the traffic jams, so they walk.W: In other words, the Romans do what everyone else does.M：Yes，but they do it differently．Everything is different．W: What do you meanM: Well, the climate is different for a start. I know you hate the rain. It doesn’t rain so much as it does in England. The sun shines more often.W: I envy them for the sun.M: I know. You hate the rain, don’t youW: I certainly do.M: And a Roman really loves life. They always eat spaghetti and drink wine.W: Not always, but they like a good meal. Lots of tourists go to Rome just for food.M: Sure. What’s the relationship between the two persons（）

A. Wife and husband.
B. Salesman and customer.
C. Teacher and student.
D. Employer and employee.

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Passage 3 Fire can help people in many ways. But it can be very dangerous. Fire can heat water, warm houses, give light and cook. But fire can burn things, too. It can bum trees, houses, animals or people. Sometimes big fires can burn forests. Nobody knows for sure how people began to use fire. But there are many interesting stories about the first time a man or a woman started a fire. One story from Australia tells about a man very, very long time ago. He went up to the sun by a rope (绳子) and brought fire down. Today people know how to make a fire with matches (火柴) . Children sometimes like to play with them. But matches can be very dangerous. One match can bum a piece of paper and then it might bum a house. A small fire can become a big fire very fast. Fire kills many people every year. So you must be careful with matches. You should also learn to put out fires. (80) Fires need oxygen(氧气). Without oxygen they will die. Cover a fire with water, sand, or sometimes with your coat. This keeps the air away from a fire and kills it. Be careful with fire, and it will help you. Be careless with fire, and it will bum you. We must be careful with fire, or it________.

A. will die
B. will warm our houses
C. might bum us
D. won’t help us

阅读以下说明和关系表，回答问题1-6。[说明] 设有三个关系学生S(学号，姓名，性别，年龄，籍贯) 课程C(课程号，课程名，任课老师，所用教材) 学生成绩SC(学号，课程号，得分) 其中规定各属性定义如下：学号：SNUM 姓名：SNAME 性别：SEX 年龄：AGE 籍贯：NATIVE 课程号：CNUM 课程名：CNAME 任课老师：TEACHER 所用教材：BOOK 得分：GRADE 试用关系代数表达式表示下列查询语句。 [问题6] 检索选修课程包含学号为2且年龄小于20的学生所修全部课程的课程号。

阅读以下说明，回答问题1-4。现有这样一个关系，用来表示某工厂工人家庭的信息。记录每个工人的工作证号、姓名和家庭住址，还包含他/她的每个孩子的身份证号、姓名和年龄，以及他／她所拥有的每部电话的电话号码和型号。已知：有一些人可能有很多部电话，这些电话可能是同一型号，也可能不是同一型号；有一些人没有电话；如果某人有电话，他的每部电话都有一个电话号码。有一些人可能有很多个孩子，有一些人没有孩子。初步设计的关系模式如下：R(身份证号，姓名，家庭住址，H身份证号，H姓名，H年龄，电话号码，型号)，其中“H身份证号，H姓名，H年龄”分别是孩子的身份证号、姓名和年龄。 [问题3] 请将该关系模式分解成BCNF的关系模式，确定主关系键。

比较群体决策和个人决策之间的利弊。