问题 单项选择题

下列生物碱的碱性强弱顺序排列正确的是

A.季铵生物碱>脂肪胺生物碱>芳胺生物碱>酰胺生物碱
B.脂肪胺生物碱>芳胺生物碱>季铵生物碱>酰胺生物碱
C.酰胺生物碱>脂肪胺生物碱>芳胺生物碱>季铵生物碱
D.芳胺生物碱>脂肪胺生物碱>季铵生物碱>酰胺生物碱
E.季铵生物碱>芳胺生物碱>脂肪胺生物碱>酰胺生物碱

答案

参考答案:A

阅读理解与欣赏

阅读下面的文章,完成小题。(10分)

云计算   钟华

①云是网络、互联网的一种比喻说法,云计算是基于互联网的相关服务的增加、使用和交

付模式。云计算被视为未来新一代信息技术变革的核心,将带来工作方式和商业模式的根本

性改变,已成为全社会关注的焦点和热点。

②云计算提供了最可靠、最安全的数据存储中心,用户不用再担心数据丢失、病毒入侵等

麻烦。很多人觉得数据只有保存在自己的电脑里才最安全,其实不然。你的电脑可能会因为

自己不小心而被损坏,或者被病毒攻击导致硬盘数据无法恢复,不法之徒则可能利用接触你电

脑的机会窃取你的数据。据报道日本核能机构电脑因为感染病毒,导致大量数据外泄。反之,

当你的文档保存在类似Google Docs的网络服务上,你就再也不用担心数据的丢失或损坏。因

为在“云”的另一端,有全世界最先进的数据中心来帮你保存数据,有全世界最专业的团队来

帮你管理信息。

③云计算对用户端的设备要求最低,使用起来也最方便。你只要有一台可以上网的电脑,

有一个你喜欢的浏览器,你要做的就是在浏览器中键入URL,然后尽情享受云计算带给你的

无限乐趣。你可以在浏览器中直接编辑存储在“云”的另一端的文档,可以随时与朋友分享信

息。因为在“云”的另一端,有专业人员帮你维护硬件,帮你安装和升级软件,帮你防范病毒和

各类网络攻击,帮你做你以前在个人电脑上所做的一切。

④云计算可以轻松实现不同设备间的数据与应用共享。不同设备的数据同步方法种类繁多,操作复杂,要在这许多不同的设备之间保存和维护最新的一份联系人信息,你必须为此付出难以计数的时间和精力。这时,你使用云计算就会让一切变得简单。在云计算的网络应用模式中,数据只有一份,保存在“云”的另一端,你的所有电子设备只需要连接互联网,就可以同时访问和使用同一份数据。你可以在任何地方用任何一台电脑找到某个朋友的电子邮件地址,可以在任何一部手机上直接拨通朋友的电话号码。

⑤云计算为我们使用网络提供了无限的可能,作为一种最能体现互联网精神的计算模型,云计算必将在不远的将来展示出强大的生命力,并将从多个方面改变我们的工作和生活。

(选自《语文报》,有删改)

小题1:云计算有哪些优点?请简要概括。(3分)

小题2:第②段中运用了哪些说明方法?有何作用?(4分)

小题3:请你从说明文语言的角度,对第④段中加点的词语进行简要分析。(3分)

单项选择题

Celebrate. Celebrate. Physicians are delighted with a Food and Drug Administration (FDA) advisory panel’s recommendation earlier this year that Vioxx and its cousins Bextra and Celebrex (all medicines known as Cox-2 inhibitors) should remain on the market, despite evidence they increase heart disease risk in some people. The panelists reached their decision after weighing all the data and concluding the benefits of these pain-relieving drugs outweighed the risks.
Specifically, these scientists acknowledged that, for some patients, these prescription drugs were uniquely effective in reducing pain from arthritis and other causes. For others—concerned about ulcers associated with aspirin and other OTC analgesics—the Cox-2 inhibitors offered the advantage of minimizing potentially serious effects of stomach irritation.
Now is an appropriate time for everyone to take a fresh look at the benefit-risk equation for Vioxx and the other Cox-2 inhibitors.
The risks-increased risk of heart disease in some who use the drugs—have been well publicized. Much less publicity has been given to a spectrum of real and potential benefits that go way beyond reduced risk of stomach irritation. These little-discussed benefits would have been lost, perhaps permanently-had Vioxx, Bextra and Celebrex been driven from shelves in pursuit of perfect safety, an unattainable goal.
For example, there is substantial evidence Cox-2 inhibitors can reduce development of colon polyps, which may become colon canceL Indeed. Celebrex is FDA-approved for those genetically prone to colon cancer. Ironically, the 2004 study that revealed the elevated heart attack risk of Vioxx was primarily designed to further establish the drug’s effectiveness in protecting against colon cancer. And while the results of that interrupted trial have not yet been published, there is good reason to believe they will confirm the protective effects against colon cancer established in research over the last 10 years.
At the time of its withdrawal from the market last fall, studies of Vioxx as well as the other Cox-2 drugs suggest that they had other anti-cancer properties as well, possibly reducing the risk of malignancies of a number of sites, including the lung and esophagus.
Had these drugs been dismissed, their untapped promise for prevention would have evaporated well before it was evaluated and applied to save lives. Fortunately, cooler and wiser heads prevailed.

The word "outweighed" underlined in Paragraph 1 is closest in meaning to ______.

A.outbalance

B.exceed

C.predominate

D.rule