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问题 填空题

太阳能LED照明路灯主要由太阳能电池板、LED灯头等部分构成．LED是一种发光二极管，通过电流能够发光，可以把电能直接转化成______能，太阳能是______能源（填“一次”或“二次”）、清洁无污染．

答案

LED是一种发光二极管，通过电流时不用经过加热灯丝直接能够发光，即把电能直接转化成光能；

太阳能是直接吸收阳光来利用的，是一次能源；

故答案为：光；一次．

多项选择题

关于基金周转率的说法，正确的是( )。

A．基金周转率是衡量基金买卖股票活跃程度的指标

B．等于基金股票交易金额的一半与基金平均持有股票市值之比

C．周转率为基金平均持股时间

D．一般来说，低周转率的基金倾向于长期持有
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单项选择题

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 (171) . Third parties can introduce risk in a variety of ways from connecting with an infected laptop to unauthorized access of network resources to (172) 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 (173) of service attacks or steal (174) information by snooping the network. As they access the corporate network, mobile and remote users inadvertently can infect the network with (175) 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.

（174）是（）

A.reserved

B.confidential

C.complete

D.mysterious
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