洋地黄治疗房颤,减慢心室率的最主要机制是() A.直接延长房室结的不应期 B.兴奋迷

题型:单项选择题

问题:

洋地黄治疗房颤,减慢心室率的最主要机制是()

A.直接延长房室结的不应期

B.兴奋迷走神经

C.减慢心房的传导

D.降低心房自律性

E.降低窦房结自律性

考点:贵州住院医师神经内科心血管内科心血管内科题库
题型:单项选择题

正式足球比赛对所用足球的质量有严格的规定,下面是编号依次为1~6的6个足球的质量检测结果(正数表示超出规定质量的克数,负数表示不足规定质量的克数).(1)﹣25,(2)﹣4,(3)﹣20,(4)+30,(5)+13,(6)﹣28.问:

(1)能否求出每只足球的质量,为什么?

(2)哪一只足球的质量最好,为什么?

题型:单项选择题

急性心肌梗死时,最先恢复正常的酶是()。

A.ALT

B.LD

C.CK-MB

D.AST

E.ALP

题型:单项选择题

阅读理解。

     The elephant was lying heavily on its side,fast asleep. A few dogs started barking at it. The elephant

woke up in a terrible anger: it chased the dogs into the village where they ran for safety. That didn't stop

the elephant. It destroyed a dozen houses and injured several people. The villagers were scared and

angry. Then someone suggested calling Parbati,the elephant princess.

     Parbati Barua's father was a hunter of tigers and an elephant tamer. He taught Parbati to ride an

elephant before she could even walk. He also taught her the dangerous art of the elephant roundup-how

to catch wild elephants.

     Parbati hasn't always lived in the jungle. After a happy childhood hunting with her father,she was sent

to a boarding school in the city. But Parbati never got used to being there and many years later she went

back to her old life. "Life in the city is too dull. Catching elephants is an adventure and the excitement lasts

for days after the chase,"she says.

     But Parbati doesn't catch elephants just for fun."My work," she says,"is to rescue man from the

elephants,and to keep the elephants safe from man." And this is exactly what Parbati has been doing for

many years. Increasingly,the Indian elephant is angry: for many years,illegal hunters have attacked it and

its home in the jungle has been reduced to small pieces of land. It is now fighting back. Whenever wild

elephants enter a tea garden or a village,Parbati is called to guide the animals back to the jungle before

they can kill.

    The work of an elephant tamer also involves love and devotion. A good elephant tamer will spend

hours a day singing love songs to a newly captured elephant."Eventually they grow to love their tamers

and never forget them. They are also more loyal than humans,"she said,as she climbed up one of her

elephants and sat on the giant,happy animal. An elephant princess indeed!

1.For Parbati, catching elephants is mainly to________.

A.get long lasting excitement

B.keep both man and elephants safe

C.send them back to the jungle

D.make the angry elephants tame

2.Before Parbati studied in a boarding school,________.

A.she spent her time hunting with her father

B.she learned how to sing love songs

C.she had already been called an elephant princess

D.she was taught how to hunt tigers

3.Indian elephants are getting increasingly angry and they revenge because________.

A.they are caught and sent for heavy work  

B.illegal hunters capture them and kill them

C.they are attacked and their land gets limited

D.dogs often bark at them and chase them

4.The passage starts with an elephant story in order to explain that in India ________.

A.people easily fall victim to elephants' attacks  

B.the manelephant relationship is getting worse

C.elephant tamers are in short supply

D.dogs are as powerful as elephants

题型:单项选择题

在杜甫的《曲江二首》中,以下哪句使用了借义的对仗方法?()

A、朝回日日典春衣,每日江头尽醉归

B、酒债寻常行处有,人生七十古来稀

C、穿花蛱蝶深深见,点水蜻蜓款款飞

D、传语风光共流转,暂时相赏莫相违

题型:单项选择题


阅读以下技术说明,根据要求回答问题1~问题3。
[说明]
某企业根据业务发展需求,建设一个内部专用网络,在网络中拥有4个物理网段,即网段1~网段4。这4个网段直接通过路由器进行连接,其网络拓扑结构如图2-18所示。其中,网段1为整个网络的核心网段,所有的服务器都托管在网段1,而网段2~网段4为普通的工作网段。其中,在网段3中的用户主要使用的应用需求如表2-8所示。


表2-8 网段3的应用需求分析表

应用名称平均事务量大小平均用户数平均会话长度每个会话发生的事务数量通信模式备注
OA系统0.03MB3601分钟6B/S该应用服务器放置于网段1
生产管理系统0.05MB2701分钟8B/S服务器位于网段1,主要用于满足生产工作管理需要
文件共享服务60MB15010分钟1C/S服务器位于网段1,主要采用Windows网络文件系统提供C/S服务
电广邮件服务1.5MB2101分钟2C/S用户通过邮件客户端访问放置于网段1中的E-mail服务器
视频监控210MB180.5分钟1P2P用户可以互相调阅不同网段的视频监控流,无须经过流媒体服务器的管理
内部交流0.09MB4801分钟6P2P用户借助于部分局域网通信软件,进行内部交流
为了简化通信流量分析的计算过程,对于服务器至客户机流量大类型、客户机至服务器流量大类型、双向流量大类型的服务通信模式分别按80/20、20/80、50/50规则进行通信流量分析。计算过程可忽略TCP、 UDP、IP等协议封装所引起的额外通信流量的影响。

通信规范说明书是通信规范分析阶段的主要产物。请用300字以内的文字简要叙述通信规范说明书的功能及其主要组成部分。

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