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Khắc phục hiện tượng không xuất hiện menu Bộ công cụ Violet trên PowerPoint và Word

12099162 Kính chào các thầy, cô. Khi cài đặt phần mềm , trên PowerPoint và Word sẽ mặc định xuất hiện menu Bộ công cụ Violet để thầy, cô có thể sử dụng các tính năng đặc biệt của phần mềm ngay trên PowerPoint và Word. Tuy nhiên sau khi cài đặt phần mềm , với nhiều máy tính sẽ...
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Người gửi: Ngô Thời Nhiệm
Ngày gửi: 15h:52' 19-03-2020
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A Reading Comprehension
Since the dawn of time, people have found ways to communicate with one another. Smoke signals and tribal drums were some of the earliest forms of communication. Letters, carried by birds or by humans on foot or on horseback, made it possible for people to communicate larger amounts of information between two places. The telegram and telephone set the stage for more modern means of communication. With the invention of the cellular phone, communication itself has become mobile.
For you, a cell phone is probably just a device that you and your friends use to keep in touch with family and friends, take pictures, play games, or send text message. The definition of a cell phone is more specific: it is a hand-held wireless communication device that sends and receives signals by way of small special areas called cells.
Walkie - talkies, telephones and cell phones are duplex communication devices: They make it possible for two people to talk to each other. Cell phones and walkie-talkies are different from regular phones because they can be used in many different locations. A walkie-talkie is sometimes called a half-duplex communication device because only one person can talk at a time. A cell phone is a full-duplex device because it uses both frequencies at the same time. A walkie-talkie has only one channel. A cell phone has more than a thousand channels. A walkie-talkie can transmit and receive signals across a distance of about a mile. A cell phone can transmit and receive signals over hundreds of miles. In 1973, an electronic company called Motorola hired Martin Cooper to work on wireless communication. Motorola and Bell Laboratories (now AT& T) were in a race to invent the first portable communication device. Martin Cooper won the race and became the inventor of the cell phone. On April 3. 1973, Cooper made the first cell phone call to his opponent at AT& T while walking down the streets of New York city. People on the sidewalks gazed at Cooper in amazement. Cooper’s phone was called A Motorola Dyna-Tac. It weighed a whopping 2.5 pounds (as compared to today’s cell phones that weigh as little as 3 01.4 ounces)
After the invention of his cell phone, Cooper began thinking of ways to make the cell phone available to the general public. After a decade, Motorola introduced the first cell phone for commercial use. The early cell phone and its service were both expensive. The cell phone itself cost about $3, 500. In 1977, AT & T constructed a cell phone system and tried it out in Chicago with over 2,000 customers. In 19H1, a second cellular phone system was started in the Washington, D.C and Baltimore area. It took nearly 37 years for cell phones to become available for general public use. Today, there are more than sixty million cell phone customers with cell phones producing over thirty billion dollars per years.
1.What is the main idea of the passage? A.the increasing number of people using cell phone B.the difference between cell phones and telephones C.the history of a cell phone D.how Cooper competed with AT& T 2.What definition is true of a cell phone? A.The first product of two famous corporation B.A hand-held wireless communication device C.Something we use just for playing games D.A version of walkie-talkie
3.The word duplex is closest meaning to ______ A.quick B. modern C.having defects D.having two parts 4.To whom did Cooper make his first cell phone call? A.his assistant at Motorola B.a person on New York street
C.a member of Hell Laboratories D.the director of his company
5.How heavy is the first cell phone compared to today’s cell phones? A.ten times as heavy as B.as heavy as C.much lighter D.2 pounds heavier
6.When did AT& T widely start their cellular phone system? A in 2001 B. in 1977
C.in 1981 D. 37 years after their first design 7.What does the word gazed mean? A.looked with admiration B.angrily looked C.glanced D.started conversation 8.The phrase tried it out refers to _______ A. made effort to sell the cell-phone B. reported on AT& T C. tested the cell-phone system D. introduced the cell-phone system

As heart disease continue to be the number-one killer in the United States, researchers have become increasingly interested in
 
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