【问题2】(1)[说明]中的几个关系仍无法实现甲公司的要求，为什么_爱下问搜题

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问题问答题

【问题2】(1)[说明]中的几个关系仍无法实现甲公司的要求，为什么(2)需要在哪个关系中增加什么数据项才能实现这个要求

答案

参考答案：

解析：因为只有product记录了单价，一旦单价发生改变，用户订单地价格就会发生改变，因此，计算一张订单将采用新的单价，不符合要求。(2)有两种方法：一是在Order表中加入一项表示订单地产品总价，二是在Order表中加入产品单价，这两种方法都能满足要求。

完形填空

When I was young, I wanted to be a teacher if I grew up，simply because I wanted to write on the chalkboard！My teachers seemed to be the   36  printers，curving their letters just so，and I wanted to do it   37 ！Now，after "higher education"，and three   38  career paths，I have come back to want to be a   39 ，but my reasons have changed. I was   40  in my years of high school，to have teachers that really   41  me as an individual, and I want to   42  this back.
A teacher's gentleness needs to be shown when    43   or encouraging the students. It is important to make the corrections in order for the students to learn.    44  ，this needs to be done in a    45   that will help to    46   the student to make the changes necessary,___47___ discouraging them from learning.Being patient is also extremely important，because the class needs to know what to    48   from the teacher.This will also help to build a better agreement with the students，and help both the teacher and students to learn more about each other.
If a teacher exhibits a true love of    49   and helping students learn，many of the qualities ___50___ above will just fall into place. The teacher that had the most    51   on me had the best fame in the school. She was strict，and she did demand a lot, but she was able to show us it was               ___52___she cared for us. She knew each of us was worth it，and she knew we each could do it. She __53___ knowledge，gently, firmly, patiently，respectfully, and most effectively. She gently encouraged us to make    54   when we needed to，and    55   us when we did. She was a true teacher, not just someone who taught，and this is the kind of teacher I hope to be.

A．cared about

B．believed in

D．thought about

C．considering

单项选择题

下列叙述中，错误的是

A．硬盘在主机箱内，它是主机的组成部分

B．硬盘是外部存储器之一

C．硬盘的技术指标之一是每分钟的转速rpm

D．硬盘与CPU之间不能直接交换数据