If you look around the room you are in right now, you’ll probably notice a number of electronics. But can you imagine if they all had to be joined together by wires (电线)? Picture the wire snaking along the floor, for example, from your smartphone to your speaker, or connecting your game controller to the computer screen, meaning you could never sit more than a couple of meters away from it. A world of electronics connected by wires wouldn’t just be untidy, but a possible danger, too. That’s where Bluetooth comes in. We’ve all heard of it — but what exactly is it?
Bluetooth is a method of short-distance (短距离) wireless communication between electronics that makes use of the power of radio waves. The idea was first thought of by Dr. Janp Haartsen at Swedish mobile company Ericsson in 1994. Things really stepped up in September 1998 when the Bluetooth Special Interest Group (SIG) was set up to develop and spread the technology. Bluetooth 1.0 came out in 1999, and a year later it began to be used in mobile phones and desktop computers. Now Bluetooth has become an increasingly popular way of solving the problem of more and more electronics needing to be connected. without having to connect everything together with wires.
But if you look at the remote control (温控器) you use to choose the program on TV, you might rightly ask yourself why Bluetooth was such a big deal. After all, connecting objects with infrared signals (红外信号) which can’t be seen had been done before. The problem with remote controls is that they need to keep what is called “line of sight”. If something is standing between the remote control and receiver, it won’t work. Because Bluetooth uses radio waves, the things standing in the way are no longer a problem.
Since its creation in the late 1990s, the technology has become more and more improved and widely used, with the 4 billionth Bluetooth objects shipped in 2020.
1.How does the writer lead in the topic “Bluetooth” in Paragraph 1?A.By describing scenes. | B.By comparing facts. | C.By telling stories. | D.By explaining reasons. |
A.started to be used in cars | B.made radio waves known to people |
C.improved and spread quickly | D.was able to connect all electronics |
A.development | B.popularity | C.standard | D.advantage |
A.Phone sellers | B.Technology fans | C.Newspaper reporters | D.History lovers |
同类型试题
y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2
y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2