2021年12月英语四级阅读真题及答案 第1套 段落匹配
uno牌的玩法 Directions:In this ction, you are going to read a passage with ten statements attached to it. Each statement contains information given in one of the paragraphs. Identify the paragraph from which the information is derived. You may choo a paragraph more than once. Each paragraph is marked with a letter. Answer the questions by marking the corresponding letter on Answer Sheet 2.馏米
Can Burglars Jam Your Wireless Security System?
[A]Any product that promis to protect your home derves careful examination. So it isn’t surprising that you’ll find plenty of strong opinions about the potential vulnerabilities of popular home-curity systems.
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[B]The most likely type of burglary (入室盗窃) by far is the unsophisticated crime of opportunity, usually involving a broken window or some forced entry. According to the FBI, crimes like the accounted roughly two-thirds of all houhold burglaries in the US in 2021.
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The wide majority of the rest were illegal, unforced entries that resulted from something like a window being left open. The odds of a criminal using technical means to bypass a curity system are so small that the FBI doesn’t even track tho statistics.
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一声叹息 [C]One of the main theoretical home-curity concerns is whether or not a given system is vulnerable to being blocked from working altogether. With wired tups, the fear is that a burglar (入室盗贼) might be able to shut your system down simply by cutting the right cable. With a wireless tup, you stick battery-powered nsors up around your home that keep an eye on windows, doors, motion, and more. If they detect something wrong while the system is armed, they’ll transmit a wireless alert signal to a ba station that will then rai the alarm. That approach will eliminate most cord-cutting concerns—but what about their wireless equivalent, jamming? With the right device tuned to the right frequency, what’s to stop a thief from jamming your tup and blocking that alert signal from ever reaching the ba station?
[D]Jamming concerns are nothing new, and they’re not unique to curity systems. Any
device that’s built to receive a wireless signal at a specific frequency can be overwhelmed by a stronger signal coming in on the same frequency. For comparison, let’s say you wanted to “jam” a conversation between two people—all you’d need to do is yell in the listener’s ear.
人生励志语录 [E] Security devices are required to list the frequencies they broadcast on—that means that a potential thief can find what they need to know with minimal Googling. They will, however, need so know what system they’re looking for. If you have a sign in your yard declaring what tup you u, that’d point them in the right direction, though at that point, we’re talking about a highly targeted, mi-sophisticated attack, and not the sort forced-entry attack that makes up the majority of burglaries. It’s easier to find and acquire jamming equipment for some frequencies than it is for others.
观的组词是什么 [F] Wireless curity providers will often take steps to help combat the threat of jamming attacks. SimpliSafe, winner of our Editor’s Choice distinction, utilizes a special system that’s capable of parating incidental RF interference from targeted jamming attacks. W
hen the system thinks it’s being jammed, it’ll notify you via push alert(推送警报).From there, it’s up to you to sound the alarm manually.
[G] SimpliSafe was singled out in one recent article on jamming, complete with a video showing the entire system being effectively bypasd with handheld jamming equipment. After taking appropriate measures to contain the RF interference to our test lab, we tested the attack out for ourlves, and were able to verify that it’s possible with the right equipment. However, we also verified that SimpliSafe’s anti-jamming system works. It caught us in the act, nt an alert to my smartphone, and also listed our RF interference on the system’s event log. The team behind the article and video in question make no mention of the system, or whether or not in detected them.
[H]We like the unique nature of that software. It means that a thief likely wouldn’t be able to Google how the system works, then figure out a way around it. Even if they could, SimpliSafe claims that its system is always evolving, and that it varies slightly from system to system, which means there wouldn’t be a universal magic formula for cracking
it. Other systems also em confident on the subject of jamming. The team at Frontpoint address the issue in a blog on its site, citing their own jam protection software and claiming that there aren’t any documented cas of successful jam attack since the company began offering wireless curity nsors in the 1980s.
[I] Jamming attacks are absolutely possible. As said before, with the right equipment and the right know-how, it’s possible to jam any wireless transmission. But how probable is it that someone will successfully jam their way into your home and steal your stuff?
