阅读下列说明，回答问题1至问题5。

【说明】

某仓储超市采用POS(Point of Sale)收银机负责前台的销售收款，为及时掌握销售信息，并依此指导进货，拟建立商品进、销、存数据库管理系统。该系统的需求分析已经基本完成，下面将进入概念模型的设计。

【需求分析结果】

1．销售业务由POS收银机来辅助实现。POS机外接条码阅读器，结账时收银员将商品的条码通过阅读输入器输入POS机中。所售商品数量默认值为1，可以由收银员修改。POS机根据输入的商品信息，打印出图22-1所示的购物清单。

2．将经销的商品分为直销商品和库存商品两大类。直销商品的保质期较短，如食品类，由供应商直接送达超市，管理员将过期的商品返还给供应商处理；库存商品由采购员向供应商提交订购单，供应商根据订购单送货。超市会不定期对库存商品按照折扣率进行打优惠。

直销商品和库存商品的送货单样表分别如图22-2、图22-3所示，其中直销商品生产批号的前六位表示生产日期。

3．超市的硬件拓扑结构如图22-4所示。

4．业务处理过程：由POS机存储每一笔销售记录，在每个工作日结束前汇总当日各商品的销售量至中心数据库(销售日汇总)：根据当日的销售日汇总更新存货表；每笔进货记入进货表中，并及时更新存货表。

【概念模型设计】

根据需求阶段收集的信息，设计的实体联系图和关系模式(不完整)如下：

1．实体联系图(如图22-5所示)

2．关系模式

销售详单(销售流水号，商品编码，数量，金额，收银员，时间)

销售日汇总(日期，商品编码，数量)

存货表(商品编码，数量)

进货表(送货号码，商品编码，数量，日期)

商品( (b) )

【问题4】

如果将商品信息只存储在中心数据库中，与在各POS机上存储其备份相比，从前台销售效率和更新商品库两方面论述各自的优缺点（不超过300字）。

III 阅读理解（共20小题；每小题2分，满分40分）

阅读下列短文，从每题所给的A、B、C和D项中，选出最佳选项，并将答案填涂在答题卡上。

I’m a 20-year-old boy, and the following is my story.

A month after I graduated from high school in August, 2007, I was coming home from swim practice in the training centre of the city and was involved in a car accident. I was so seriously injured that I was in a coma for more than two months at Prince Georges Hospital.

I suffered a lot from the experience of dying eight times during my coma and I couldn’t open my mouth to talk or to communicate when I eventually came around. At that time, it seemed that walking was never going to happen again due to all the extreme injuries. Just like my body, my dreams were completely destroyed. But I was not going to let my injuries stop me from realizing my dreams.

After receiving a total of 15 operations and 36 blood transfusions, I had to make every great effort to learn to talk, eat, walk, shower, and live on my own again. When I was out of hospital, I still had to go to outpatient therapy in Waldorf, Maryland. After I spent a few months in a wheelchair, I took baby steps to walk on my own. It was a miracle that I was able to walk again, but I still wanted to prove that I could not only walk, but also run. When it came true, I wanted to get back into the pool again. After having a few lung tests, I was able to go in the pool a little bit each week. After a few months of swim training, I began my freshman year at St. Mary’s College of Maryland and then became a proud member of the swim team.

By telling my story, I want to make a positive influence on the world. I am just trying to live each day to the fullest and inspire other people never to give up their dreams no matter how bad a situation is to them. I remember when I was still in my hospital bed, I would have my mom and dad push me round in my wheelchair to the other rooms to see the other patients and chat with them and their family members. I wanted to let them know that everything was going to be okay. Somehow, things would work out for the best.

41. The underlined word “coma” in Paragraph 2 probably has the meaning of “_______”.

A. operation       B. unconsciousness     C. treatment          D. emergency

42. According to Paragraph 3, it can be inferred that the author _______.

A. was unable to talk or communicate        B. was in despair

C. faced physical and mental challenges      D. felt anxious about his state

43. What is the correct order of the following events?

a. went to outpatient therapy

b. received membership of the swim team

c. was pushed around to visit other patients

d. walked like a baby

e. learnt to live all by himself

A. d、a、c、b、e                       B. e、c、d、a、b

C. d、c、a、b、e                       D. e、c、a、d、b

44. In the last paragraph, the author mainly wants to show _______.

A. his positive influence on other patients    B. his meaningful life

C. his purpose of sharing his story          D. his great achievements

45. The best title for the passage would be “_______”.

A. Attitude is everything                  B. Actions speak louder than words

C. Everything happens for a reason        D. A good beginning is half done