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直方图是描述统计分布的唯一形式。
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下列关于登记误差说法正确的是（）。
阅读下面这篇短文，短文后有2项测试任务；(1)第23～26题要求．从所给的6个选项中为第2～5段每段选择1个正确的小标题；(2)第27～30题要求从所给的6个选项中选择4个正确选项，分别完成每个句子。 Compact Disks 1 If someone says to you your music CDs don’t really hold any music on them, and they only have numbers recorded on them, you may not believe it. In fact, he is right in that sound is actually recored onto the CDs as special numbers --a digital code. The code is pressed onto the CD as bumps on a long spiral track almost five kilometers long. These bumps are an average of 0.5 microns wide. 2 A small laser beam shines onto the bumps as the CD turns. The light is reflected back to a receiver that records how the laser light bounces back. This lets the CD player turn the reflected light back into the original code. This means you can hear the original code as music. 3 Digital codes are used with many technologies. E-mail needs these kinds of code numbers. Space probes communicate with their ground station on earth using digital codes. Bar codes are read as digital codes in computer systems. Digital communications with cell phones need digital codes. Weather radios also tune in to specific signals using these codes. 4 There are many types of compact disks. One format is called CD-RWs. They can be’ recorded on and re-recorded on (rewritten on) as you would do with a floppy disk. Another format is the CD-ROM. The technology for recording on these disks is different from other CDs. These CDs have a dye layer that the CD writer can darken or leave clear. The clear and dark spots are the digital code. CD-ROM stands for Compact Disc -- Read Only Memory. This disk is like a "super" floppy disk that can hold lots of information. One CD-ROM can h01d the same amount of data as 500 floppy disks. Information is permanently recorded onto it. Computer games and other programs are considered to be CD-ROMs. 5 CDs were first sold to the public in 1982, These CDs still play. well and sound fine. Current CDs are expected to last between 70 to 200 years. Of course, you can make sure your CDs last a long time by taking care of them. 6 Science keeps on developing. It may not be many more years before a completely new technology is invented and introduced to the public for music recording. In the meantime, there is no doubt you will continue to enjoy listening to your favorite music on CDs and playing your favorite computer games on CD-ROMs, Space probes could not ______ without using digital codes.
阅读下面这篇短文，短文后有2项测试任务；(1)第23～26题要求．从所给的6个选项中为第2～5段每段选择1个正确的小标题；(2)第27～30题要求从所给的6个选项中选择4个正确选项，分别完成每个句子。 Compact Disks 1 If someone says to you your music CDs don’t really hold any music on them, and they only have numbers recorded on them, you may not believe it. In fact, he is right in that sound is actually recored onto the CDs as special numbers --a digital code. The code is pressed onto the CD as bumps on a long spiral track almost five kilometers long. These bumps are an average of 0.5 microns wide. 2 A small laser beam shines onto the bumps as the CD turns. The light is reflected back to a receiver that records how the laser light bounces back. This lets the CD player turn the reflected light back into the original code. This means you can hear the original code as music. 3 Digital codes are used with many technologies. E-mail needs these kinds of code numbers. Space probes communicate with their ground station on earth using digital codes. Bar codes are read as digital codes in computer systems. Digital communications with cell phones need digital codes. Weather radios also tune in to specific signals using these codes. 4 There are many types of compact disks. One format is called CD-RWs. They can be’ recorded on and re-recorded on (rewritten on) as you would do with a floppy disk. Another format is the CD-ROM. The technology for recording on these disks is different from other CDs. These CDs have a dye layer that the CD writer can darken or leave clear. The clear and dark spots are the digital code. CD-ROM stands for Compact Disc -- Read Only Memory. This disk is like a "super" floppy disk that can hold lots of information. One CD-ROM can h01d the same amount of data as 500 floppy disks. Information is permanently recorded onto it. Computer games and other programs are considered to be CD-ROMs. 5 CDs were first sold to the public in 1982, These CDs still play. well and sound fine. Current CDs are expected to last between 70 to 200 years. Of course, you can make sure your CDs last a long time by taking care of them. 6 Science keeps on developing. It may not be many more years before a completely new technology is invented and introduced to the public for music recording. In the meantime, there is no doubt you will continue to enjoy listening to your favorite music on CDs and playing your favorite computer games on CD-ROMs, The laser beam-emitting device and the receiver are considered to ______ of a CD player.
阅读下面的短文，文中有15处空白，每处空白给出了4个选项，请根据短文的内容从4个选项中选择1个最佳答案。 Animal’s "Sixth Sense" A tsunami was triggered by an earthquake in the Indian Ocean in December, 2004. It killed tens of thousands of people in Asia and East Africa. Wild animals, (51) , seem to have escaped that terrible tsunami. This phenomenon adds weight to notions that they possess a "sixth sense" for (52) , experts said. Sri Lankan wildlife officials have said the giant waves that killed over 24,000 people along the Indian Ocean island’s coast clearly (53) wild beasts, with no dead animals found. "No elephants are dead, not (54) a dead rabbit. I think animals can (55) disaster. They have a sixth sense. They know when things are happening," H.D. Ratnayake, deputy director of Sri Lanka’s Wildlife Department, said about one month after the tsunami attack. The (56) washed floodwaters up to 2 miles inland at Yala National ’Park in the ravaged southeast, Sri Lanka’s biggest wildlife (57) and home to hundreds of wild elephants and several leopards. "There has been a lot of (58) evidence about dogs barking or birds migrating before volcanic eruptions or earthquakes. But it has not been proven," said Matthew van Lierop, an animal behavior (59) at Johannesburg Zoo. "There have been no (60) studies because you can’t really test it in a lab or field setting," he told Reuters. Other authorities concurred with this (61) . "Wildlife seem to be able to pick up certain (62) , especially birds... there are many reports of birds detecting impending disasters," said Clive Walker, who has written several books on African wildlife. Animals (63) rely on the known senses such as smell or hearing to avoid danger such as predators. The notion of an animal "sixth sense" -- or (64) other mythical ’power -- is an enduring one which the evidence on Sri Lanka’s ravaged coast is likely to add to. The Romans saw owls (65) omens of impending disaster and many ancient cultures viewed elephants as sacred animals endowed with special powers or attributes.
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