62．The underlined sentence means . A．the war in Vietnam wasn’t serious at all B．the war in Vietnam was different from that in Kosovo. C．the US will send more troops to Kosovo than that to Vietnam D．ground troops to Kosovo will cause an even greater disaster C For centuries, people wondered how big the Earth was. Unfortunately, as long as they thought the Earth was flat, no one was able to figure out its size. Gradually, however, people began to realize that the Earth was really round. Then, in the third century BC, a Greek man named Eratosthenes had an idea. Eratosthenes was sure that the Earth was a sphere. He used the sun and geometry to figure out the size of the Earth. He calculated that the circumference of the Earth was 28,600 miles.The true size of the Earth is 25,000 miles.Eratosthenes’ measurement was wrong, but it was very close to the truth. For many centuries after Eratoshenes lived, people made maps of the Earth. However, they did not know very much about the world outside of Europe, Asia, and north Africa. Mapmakers could not draw accurate maps of the Earth until people began traveling around the world in the fifteenth century, mapping small areas each time. In the eighteenth and nineteenth centuries, people began making correct maps of countries, but the first accurate maps of the world were not made until the 1890s. Maps today are reliable, inexpensive, and easy to understand. People depend on maps every day. What would our lives be like without them? 【查看更多】
