诊疗科、医师和患者的关系模式及它们之间的E-R图如下所示：诊_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题单项选择题

诊疗科、医师和患者的关系模式及它们之间的E-R图如下所示：

诊疗科（诊疗科代码，诊疗科名称）

医师（医师代码，医师姓名，诊疗科代码）

患者（患者编号，患者姓名）

其中，带实下划线的表示主键，虚下划线的表示外键。若关系诊疗科和医师进行自然连接运算，其结果集为（）元关系。医师和患者之间的治疗观察关系模式的主键是（）。

医师和患者之间的治疗观察关系模式的主键是（）

A．医师姓名、患者编号

B．医师姓名、患者姓名

C．医师代码、患者编号

D．医师代码、患者姓名

答案

参考答案：C

解析：

医师和患者之间的治疗观察之间是一个多对多的联系，多对多联系向关系模式转换的规则是：多对多联系只能转换成一个独立的关系模式，关系模式的名称取联系的名称，关系模式的属性取该联系所关联的两个多方实体的主键及联系的属性，关系的码是多方实体的主键构成的属性组。由于医师关系的主键是医师代码，患者关系的主键是患者编号，因此，根据该转换规则医师和患者之间的治疗观察关系模式的主键是医师代码和患者编号。正确答案是C。

单项选择题

药品广告须经（）。

A.省级药监部门批准，发给证书

B.审批，发给药品广告批准文号

C.企业所在地省级药监部门批准，并发给药品广告批准文号

D.国家药监部门批准，可在全国任何地方做广告

E.所在地的县级药监部门批准，发给证明（2009年考试真题）

完形填空

I finished my last work of the week and could hardly wait to get home, take off my nursing shoes, and relax.
As I approached(走近) my   36 , I saw one of my   37  standing by the bus stop. I thought it would only take a couple of extra minutes to give her a ride home, and besides, it was   38  cold to be standing outside on the coldest   39  in January. I didn’t know where she lived, but I was   40  I would be able to find my way back.
We   41  about our work as I drove and before we knew it, we arrived at   42  house. I started driving back.   43  looked familiar, but at first that didn’t bother me. But soon I   44  something wrong. I   45  nothing. But I told myself to stay   46 .
I was beyond neighborhoods, streets and   47  streetlights. I no longer knew where I was now. How could I be so stupid! I looked down at my   48 . It was now 2:30 a.m. My gas was slowly running out. I   49  the car and turned off the engine. In total defeat, I put my head down on the wheel,   50 . Then I raised my head and   51  a shadow down the road in front of me. I turned my headlights on. A car! I drove a little   52 , got out of my car and knocked on the window of that car. An elderly man   53  rolled his window down.
I said that I didn’t know how to get back into town. In silence, he started driving. I ran back to my car and drove   54  him. Finally I recognized a(n)   55  street. As I turned to head home, the car disappeared. Then I pulled into my driveway (车道) when the warning light for my gas tank (汽油箱) turned on.
Though so many years have passed, I still thank the old man from my deepest heart.