下列有关数据库的描述，正确的是( )。A．数据处理是将信息

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问题单项选择题

下列有关数据库的描述，正确的是( )。

A．数据处理是将信息转化为数据的过程

B．数据的物理独立性是指当数据的逻辑结构改变时，数据的存储结构不变

C．关系中的每一列称为元组，一个元组就是一个字段

D．如果一个关系中的属性或属性组并非该关系的关键字，但它是另一个关系的关键字，则称其为本关系的外关键字

答案

参考答案：D

解析：数据处理是指将数据转换成信息的过程，故选项A)叙述错误；数据的物理独立性是指数据的物理结构的改变，不会影响数据库的逻辑结构，故选项B)叙述错误；关系中的行称为元组，对应存储文件中的记录，关系中的列称为属性，对应存储文件中的字段，故选项C)叙述错误。

单项选择题

正常分娩机转俯屈是胎头遇到阻力以枕额径转为（）

A．双顶径

B．枕颏径

C．枕下前囟径

D．双电径

E．双颞径

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阅读理解

     Many people catch a cold in the springtime or fall. It makes us wonder… if scientists can send a man to
the moon, why can't they find a cure for the common cold? The answer is easy. There are actually
hundreds of kinds of cold viruses out there. You never know which one you will get, so there isn't a cure
for each one.
     When a virus attacks your body, your body works hard to get rid of it. Blood rushes to your nose and
cause a block in it. You feel terrible because you can't breathe well, but your body is actually eating the
virus. Your temperature goes up and you get a fever, but the heat of your body is killing the virus. You also have a runny nose to stop the virus from getting into your cells. You may feel miserable, but actually your
wonderful body is doing every- thing it can to kill the cold.
     Different people have different cures for Colds. In the United States and some other countries, for
example, people might eat chicken soup to make themselves" feel better. Some people take hot baths and
drink warm liquids (流汁). Other people take medicine to stop Various symptoms (症状) of colds.
     There is one interesting thing to note" some scientists say taking medicines when you have a cold is
actually bad for you. The virus stays in you longer because your body doesn't have a way to fight it and kill
it.
Bodies can do an amazing job on their own. There is a joke, however, on taking medicine when you have a cold. It goes like this:
     It takes about one week to get over a cold if you don't take medicine, but it takes only seven days
to ~et over a cold if you take medicine.

Title	How Much You Know About the Common (1) ______
Introduction	◆ People catch a cold (2) ______ in spring or fall. ◆ A (3) ______ of cold viruses exist everywhere. ◆ It is hard to find a cure for each cold.
The symptoms of the common cold	◆ The body's blood as well as its temperature (4) ______, causing a fever. ◆ You will find that you have some difficulty (5) _______ ◆ You have a runny nose, which makes you feel miserable.
The ways of (6) _____ with the common cold	◆ Drinking chicken soup to help you (7) _____ ◆ Taking a hot bath and drinking warm liquids. ◆ Taking some medicine.
(8) ____ by scientists	◆ Taking medicine when having a cold will do (9) ______ to the body. ◆ Taking medicine or not will take you one week to (10) _____ the common cold.

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