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【单选题】
In the 90's, people went crazy about wireless. Electronic communications once thought bound permanently to the world of cables and hard-wired connections suddenly were sprung free, and the possibilities seemed endless. Entrenched monopolies would fall, and a new uncabled era would usher in a level of intimate contact that would not only transform. business but change human behavior. Such was the view by the end of that groundbreaking decade—the 1890s. To be sure, the wild publicity of those days wasn't all hot air. Marconi's 'magic box' and its contemporaneous inventions kicked off an era of profound changes, not the least of which was the ad vent of broadcasting. So it does seem strange that a century later, the debate once more is about how wireless will change everything. And once again, the noisy confusion is justified. Changes are on the way that are arguably as earth shattering as the world's first wireless transformation. Certainly a huge part of this revolution comes from introducing the most powerful communication tools of our time. Between our mobile phones, our BlackBerries and Treos, and our Wi-Fi (Wireless Fidelity) computers, we're always on and always connected—and soon our cars and our appliances will be, too. While there has been considerable planning for how people will use these tools and how they'll pay for them, the wonderful reality is that, as with the Internet, much of the action in the wireless world will ultimately emerge from the imaginative twists and turns that are possible when dig ital technology trumps the analog mindset of telecom companies and government regulators. Wi-Fi is itself a shining example of how wireless innovation can shed the tethers of conventional wisdom. At one point, it was assumed that when people wanted to use wireless devices for things other than conversation, they'd have to rely on the painstakingly drawn, investment-heavy standards adopted by the giant corporations that earn a lot through your monthly phone bill. But then some re searchers came up with a new communications standard exploiting an unlicensed part of the spectrum. It was called 802.11, and only later sexed up with the name Wi-Fi. Though the range of signal was only some dozens of meters, Wi-Fi turned out to be a great way to wirelessly extend an Internet connection in the home or office. A new class of activist was born: the bandwidth liberator, with a goal of extending free wireless Internet to anyone venturing within the range of a free hotspot. Meanwhile, Apple Computer seized on the idea as a consumer solution, others followed and now Wi-Fi is as common as the modem once was. Wireless technology is introduced as
A.
an important fruit in daily life.
B.
a supplement to cable communications.
C.
the opening of a new uncabled era.
D.
a new type of monopoly.
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举一反三
【多选题】下列哪些是急性毒性作用的观察指标
A.
体温、毛色、体重
B.
死亡时间
C.
死亡后尸体病理检查
D.
雄性精子或雌性卵子形态
E.
叫声怪异、惊厥
【多选题】下列哪些是急性毒性作用的观察指标( )
A.
死亡后尸体病理检查
B.
死亡时间
C.
叫声怪异、惊厥
D.
体温、毛色、体重
【多选题】多选 (3 分 ) 下列哪些是急性毒性作用的观察指标
A.
体温、毛色、体重
B.
死亡时间
C.
叫声怪异、惊厥
D.
死亡后尸体病理检查
【多选题】下列哪些是急性毒性作用的观察指标
A.
雄性精子或雌性卵子形态
B.
死亡后尸体病理检查
C.
死亡时间
D.
体温、毛色、体重
【多选题】下列哪些是急性毒性作用的观察指标
A.
体温、毛色、体重
B.
叫声怪异、惊厥
C.
死亡后尸体病理检查
D.
死亡时间
【多选题】下列关于超声回弹综合法检测混凝土强度的叙述,正确的是()
A.
一般来说,对同一构件,浇筑表面的回弹值比浇筑底面的回弹值大
B.
如超声检测采用单面平测时,测区尺寸宜为400mmx400mm
C.
测区布置在浇筑表面或底面时,超声检测的声时值也需进行修正
D.
超声回弹综合法无需检测混凝土碳化深度
【多选题】对下列句子的语法现象表述正确的是
A.
何盟之有? 宾语前置
B.
诸侯先迎之者富而兵强 定语后置
C.
君三泣臣矣 泣 :使动用法
D.
夫子所谓生死而肉骨 肉 :使动用法
【判断题】超声回弹综合法检测结构混凝土强度时,不用做碳化深度试验。()
A.
正确
B.
错误
【多选题】下列哪些是急性毒性作用的观察指标
A.
死亡时间
B.
雄性精子或雌性卵子形态
C.
死亡后尸体病理检查
D.
叫声怪异、惊厥
【单选题】超声回弹综合法检测混凝土强度需采用超声仪和回弹仪,在结构混凝土的同一个测区分别测量()
A.
波幅和回弹值
B.
波形和回弹值
C.
声时值和碳化深度
D.
声时值和回弹值
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