問題詳情

第 40 至 43 題為題組Flickering lamps can induce headaches. But if the flickering happens millions of times a second—farfaster than the eye can see or the brain process—then it might be harnessed to do something useful, liketransmitting data. This is the idea behind Li-Fi, or Light Fidelity. The term Li-Fi was coined by Universityof Edinburgh Professor Harald Haas in a 2011 TED Talk, where he introduced the idea of “wireless datafrom every light.” Today, Li-Fi has developed into a wireless technology that allows data to be sent at highspeeds, working with light-emitting diodes (LEDs), an increasingly popular way to illuminate public areasand homes.Using LED lights as networking devices for data transmission, Li-Fi has several advantages over WiFi(Wireless Fidelity). First, Li-Fi allows for greater security on local networks, as light cannot penetratewalls or doors, unlike radio waves used in Wi-Fi. As long as transparent materials like glass windows arecovered, access to a Li-Fi channel is limited to devices inside the room, ensuring that signals cannot behacked from remote locations. Also, Li-Fi can operate in electromagnetic sensitive areas such as aircraftcabins, hospitals, and nuclear power plants, for light does not interfere with radio signals. The mostsignificant advantage of Li-Fi is speed. Researchers have achieved speeds of 224 gigabits per second in labconditions, much faster than Wi-Fi broadband.How could Li-Fi enrich daily life? Anywhere there is LED lighting, there is an opportunity for Li-Fienabled applications. Li-Fi-enabled street lights could provide internet access to mobile phones, makingwalking at night safer. The LED bulbs in traffic lights could provide drivers with weather conditions andtraffic updates. Li-Fi could help with tourism by providing an easier access to local information. At home,smart light could also provide parents with solutions to their children’s Internet addiction: Just turn off thelights and you’ve turned off their access.When 14 billion light bulbs mean 14 billion potential transmitters of wireless data, a cleaner, a greener,and even a brighter future is on the way.
40. What is this passage mainly about?
(A) A new design in lighting.
(B) Wireless transmission through illumination.
(C) Radio interference in public areas.
(D) Potential applications of Li-Fi for military use.

參考答案

答案：B
難度：適中0.5
統計：A(0),B(0),C(0),D(0),E(0)

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