问题
选择题
由同种物质制成的四个正方体A、B、C、D，它们的边长分别为1cm，2cm，3cm，4cm．质量依次为3g，24g，64g，192g．则其中有一个肯定是空心的，它是（ ）
A．A
B．B
C．C
D．D
答案
答案：C
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由同种物质制成的四个正方体A、B、C、D，它们的边长分别为1cm，2cm，3cm，4cm．质量依次为3g，24g，64g，192g．则其中有一个肯定是空心的，它是（ ）
A．A
B．B
C．C
D．D
答案：C
Complete the following passage by using the words in the box. Each word can only be used once. Note that there is one word more than you need.
The continued growth suggests that the __2__ economic decline has not hit plans to build fiber networks. Sweden __3__ the list of nations applying the technology, with 10.9% of its broadband customers using fiber. Karel Helsen, president of Europe’s Fiber-To-The-Home Council, said the growth matched predictions that were __4__ when the credit crisis started to make itself felt. “The numbers in 2009 are in line with the latest forecasts,” said Mr. Helsen. By 2012, the FTTH Council expects that 13 million people across 35 European nations will have their broadband delivered by fiber. Such services would start at a speed of 100 megabits per second (mbps), said Mr. Helsen. Around Europe more than 233 projects were underway to lay the fibers that would __5__ homes or buildings to the net, said Mr. Helsen. Many of those, he said, were being operated by local governments or smaller net firms. Local governments were interested in FTTH because of the economic and social __6__ it brought in its wake, said Mr. Helsen. The low delay in high-speed fiber networks made __7__ new uses of broadband, he said. “No delay is very important,” he said, “specifically if you talk about __8__ that are time-dependent such as personal communications, conference calls or video calls where delays cause a lot of trouble.” While early FTTH services were __9__ in cities, said Mr. Helsen, many more were reaching out to rural areas for e-health and e-learning projects. |