Anewmethodofdeliveringdata,whichusesthevisiblespectrum(...

问题详情：

A new method of delivering data, which uses the visible spectrum (光谱) rather than radio waves, has been tested in a working office.

Li-fi can deliver internet access 100 times faster than traditional wi-fi, offering speeds of up to 1Gbps (gigabit per second). It requires a light source, such as a standard LED bulb, an internet connection and a photo detector.

It was tested this week using a li-fi-enabled light bulb to transmit data at speeds of 1Gbps. Laboratory testes have shown theoretical speeds of up to 224Gpbs. When tested in an office, it allowed workers to access the internet and in an industrial space, where it provided a smart lighting solution. Chief executive Deepak Solanki said that the technology could reach consumers “within three or four years”.

The term li-fi was first coined by Prof Haas, who demonstrated the technology at a Ted conference in 2011. His talk, which has now been watched nearly two million times, showed an LED lamp streaming video. Prof Haas described a future when billions of light bulbs could become wireless hotspots.

One of the big advantages of li-fi is the fact that, unlike wi-fi, it does not interfere with other radio signals, so could be used on aircraft and in other places where interference is an issue.

However, the technology also has its drawbacks—most notably the fact that it cannot be used outdoors in direct sunlight, because that would interfere with its signal. Neither can the technology travel through walls so initial use is likely to be limited to some places.

29. Which of the following will be the best title of this passage?

   A. The drawbacks of traditional Wi-fi            B. The advantages of Li-fi

   C. Li-fi 100 times faster than Wi-fi                D. Li-fi and Wi-fi

30. Which of the following statements is TRUE?

   A. Traditional wi-fi can reach speeds of up to 1Gbps.

   B. The new technology has been put into use by consumers.

   C. Deepak Solanki showed the new technology at a conference in 2011.

   D. Li-fi can’t be used without a light source, an internet connection or a photo detector.

31. This passage may be ____________.

   A. a piece of news                     B. a science fiction

   C. a fashion magazine              D. a product brochure

【回答】

CDA

知识点：阅读理解

题型：阅读理解