材料一：唐太宗说：“秦始皇平六国，隋炀帝富有四海，既骄且逸，一朝而败，吾亦何得自

一种货币成为自由外汇必须具备的特征包括()

A.普遍接受性 

B.外币性 

C.区域性 

D.收益性 

E.可兑换性

To compete in today’s fast-paced competitive environment, organizations are increasingly allowing contractors, partners, visitors and guests to access their internal enterprise networks. These users may connect to the network through wired ports in conference rooms or offices, or via wireless access points. In allowing this open access for third parties, LANs become ___19___. Third parties can introduce risk in a variety of ways from connecting with an infected laptop to unauthorized access of network resources to ___20___ activity. For many organizations, however, the operational complexity and costs to ensure safe third party network access have been prohibitive. Fifty-two percent of surveyed CISOs state that they currently use a moat and castle’s security approach, and admit that defenses inside the perimeter are weak. Threats from internal users are also increasingly a cause for security concerns. Employees with malicious intent can launch ___21___ of service attacks or steal ___22___ information by snooping the network. As they access the corporate network, mobile and remote users inadvertently can infect the network with ___23___ and worms acquired from unprotected public networks. Hackers masquerading as internal users can take advantage of weak internal security to gain access to confidential information.

22（）

A．reserved

B．confidential

C．complete

D．mysterious

常规技术设计中哪方面的知识使之可以区别于科学知识？

非政府组织的特点有（）

A、营利性

B、自治性

C、公益性

D、服务性

老空积水突水征兆主要有（）等种。

A、水量补给量较差

B、岩缝中见到淤泥

C、水为红色

D、水味发涩

E、发出臭鸡蛋味