问题 单项选择题

WiFi依赖看不见的无线电波传输,设备功率越来越大,局部电磁辐射势必增强;无线信号穿墙而过,网络信息不安全。这些安全隐患,在可见光通讯中“一扫而光”。光谱比无线电频谱大10000倍,意味着更大的带宽和更高的速度,网络设置又几乎不需要任何新的基础设施。Lifi技术本身也有其局限性,例如若灯光被阻挡,网络信号将被切断。目前的一系列关键技术产品,都是研究人员“动手做”,还没有商用的芯片组,要像WiFi那样走进千家万户,还有很长的路要走。下列说法与原文不符的是()

A.LiFi技术致力于借助灯光传输信号

B.WiFi技术在信息安全方面存在隐患

C.LiFi完成网络设置无需任何基础设施

D.WiFi目前已经得到大规模的普遍应用

答案

参考答案:C

解析:

本题为细节理解题,需要逐一对比原文。首先由“Lifi技术本身也有其局限性,若灯光被阻挡,网络信号将被切断。”可知,A选项符合文意。由“„„这些安全隐患”可知,B选项符合文意。由最后一句可知D选项符合文意。C选项原文是说“新的基础设施”,不是任何基础设施,故本题选C选项。

单项选择题

Randy Kraus was paralyzed. His left side was useless. But his right hand was (1) enough to lift a bucket to his forehead. Once, he’d been a police officer and owned a private-eye agency. Once, he’d been p and able. Now, he felt he was nothing.

His (2) started with Parkinson’s disease, but it didn’t (3) there. In July 2002, the 60 year old Kraus went into the hospital for an operation to control the shaking. (4) , during the operation, he had a stroke. He was paralyzed. The (5) man, who loved golf, could think, but couldn’t (6) . Kraus wanted the doctors to (7) it to him straight. "You may never walk again, " they told him. "Maybe you won’t (8) be able to talk. "

Once at home, he (9) he couldn’t lift a fork or take a drink by himself. Physical treatment was so painful and slow. What did he have to (10) for So now Kraus held the gun against his head. (11) the cold metal on his skin, he began to consider not his pain, but the pain he (12) cause his wife, daughters and grandchildren. He didn’t pull the trigger.

"You are where you are", his exercise physiologist, Andrew Garud told him. "The pace would be slow; the pain would be (13) . But as long as you are (14) , you have the ability to get better. " After three months of (15) with Garud, Kraus wanted to see if he could (16) . He could. Then he took three steps, sat down and cried like a baby. One step (17) to another. Next he managed a short walk. It was the hardest (18) of Kraus’s life.

Garud kept saying he could (19) more. Now, Kraus can brush his teeth, shave himself and get around the house with a walker. Little success only the paralyzed can (20) understand.

12().

A.should

B.must

C.would

D.need

单项选择题