Questions 31 to 40 are based on the following passage.
【真题来源：2016年12月大学英语四级真题（第一套）Part Ⅲ，Section B，第36-45题】
Can Burglars Jam Your Wireless Security System?
A) Any product that promises to protect your home deserves careful examination. So it isn't surprising that you'll find plenty of strong opinions about the potential vulnerabilities of popular home-security systems.
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 these accounted roughly two-thirds of all household burglaries in the US in 2013.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 security system are so small that the FBI doesn't even track those statistics.
C) One of the main theoretical home-security concerns is whether or not a given system is vulnerable to being blocked from working altogether. With wired setups, 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 setup, you stick battery-powered sensors 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 base station that will then raise 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 setup and blocking that alert signal from ever reaching the base station?
D) Jamming concerns are nothing new, and they're not unique to security 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.
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 setup you use, that'd point them in the right direction, though at that point, we're talking about a highly targeted, semi-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.
F) Wireless security 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 separating incidental RF interference from targeted jamming attacks. When 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 bypassed with handheld jamming equipment. After taking appropriate measures to contain the RF interference to our test lab, we tested the attack out for ourselves, 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, sent 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 seem confident on the subject of jamming. The team at Frontpoint addresses the issue in a blog on its site, citing their own jam protection software and claiming that there aren't any documented cases of successful jam attack since the company began offering wireless security sensors 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?
J) Let's imagine that you live in a small home with a wireless security setup that offers a functional anti-jamming system. First, a thief is going to need to target your home, specifically. Then, he's going to need to know the technical details of your system and acquire the specific equipment necessary for jamming your specific setup. Presumably, you keep your doors locked at night and while you're away. So the thief will still need to break in. That means defeating the lock somehow, or breaking a window. He'll need to be jamming you at this point, as a broken window or opened door would normally release the alarm. So, too, would the motion detectors in your home, so the thief will need to continue jamming once he's inside and searching for things to steal. However, he'll need to do so without tripping the anti-jamming system, the details of which he almost certainly does now have access to.
K) At the end of the day, these kinds of systems are primarily designed to protect against the sort of opportunistic smash-and-grab attack that makes up the majority of burglaries. They're also only a single layer in what should ideally be a many-sided approach to securing your home, one that includes common sense things like sound locks and proper exterior lighting at night. No system is impenetrable, and none can promise to eliminate the worst case completely. Every one of them has vulnerabilities that a knowledgeable thief could theoretically exploit. A good system is one that keeps that worst-case setting as improbable as possible while also offering strong protection in the event of a less-extraordinary attack.
It is possible for burglars to make jamming attacks with the necessary equipment and skill.
注意抓住题干中的关键信息make jamming attacks with the necessary equipment and skill。文中论及有了必要的设备和技术，盗贼就可能进行干扰性攻击的内容出现在I段，该段第二句提到，正如之前提到的，有了合适的设备和正确的技术，任何无线传输都有可能被干扰。由此可知，题干是对原文的同义转述。题中lIt is possible for burglars to make jamming attacks对应原文中的it's possible to jam any wireless transmission，而with the necessary equipment and skill对应原文中的with the right equipment and the rightknow-how，故答案为I。
Interfering with a wireless security system is similar to interfering with a conversation.
注意抓住题干中的关键信息Interfering with a wireless security system和similar to interfering with a conversation。文中段落论及干扰一个无线安全系统和干扰一个对话很相似的内容出现在D段，该段前两句提到，干扰问题并不是什么新鲜事，而且它们也不是安全系统所独有的。任何被设定在某个特定频率下接收无线信号的装置都能被来自同一频率更强大的信号击垮。接着最后一句提到，打个比方来说，假设你想“干扰"两个人之间的谈话，你需要做的就是在听者的耳边大声叫喊。由此可见，题干是对D段内容的概括总结，故答案为D。题中is similar to对应原文中的for comparison，而to interfering with a conversation对应原文中的to "jam" a conversation between two people。
A burglar has to continuously jam the wireless security device to avoid triggering the alarm, both inside and outside the house.
注意抓住题干中的关键信息continuously jam the wireless security device to avoid triggering the alarm。文中段落论及盗贼必须不断地干扰无线安全装置从而避免触发房屋内外的警报器的内容出现在J段，该段前半部分主要讲述盗贼在进行干扰之前需要做的事情，接下来倒数第二、三句提到，这个时候他就需要干扰你，因为打破窗户或者撬开门通常会触发警报装置。同样，你家里的移动检测器也会触发警报装置，因此一旦盗贼入室并翻找财物的话，他就需要继续进行干扰。由此可见，题干是对原文的概括总结，故答案为J。题中A burglar has to continuously jam the wireless security device对应原文中的the thief will need to continue jamming once he's inside and searching for things to steal。
SimpliSafe provides devices that are able to distinguish incidental radio interference from targeted jamming attacks.
注意抓住题干中的关键信息SimpliSafe和distinguish incidental radio interference from targeted jamming attacks。文中段落论及SimpliSafe提供能够将偶发的射频干扰和有针对性的干扰攻击区分开的装置的内容出现在F段。该段第二句提到，SimpliSafe是我们的“编辑选择奖"荣誉产品得主，它使用了一个特殊的系统，能够将偶发的射频干扰与有针对性的干扰攻击区分开。由此可见，题干是对原文的同义转述，故答案为F。题中SimpliSafe provides devices对应原文中的SimpliSaf...utilizes a special system，而that are able to distinguish incidental radio interference from targeted jamming attacks对应原文中的that's capable of separating incidental RF interference from targeted jamming attacks。
Only a very small proportion of burglaries are committed by technical means.
注意抓住题干中的关键信息burglaries are committed by technical means。文中段落论及极少数入室盗窃是通过技术手段实施的内容出现在B段，该段前两句提到,迄今为止，发生频率最高的一种入室盗窃是单纯的机会主义犯罪行为，通常包括破坏性入室盗窃或者是某种强行性入室盗窃。根据美国联邦调查局所说，像这样的犯罪行为大约占2013年美国所有家庭入室盗窃的三分之二。紧接着第三句提到，剩下的三分之一家庭盗窃当中，大多数是属于由类似一扇窗户忘记关等原因而导致的非强行入室盗窃的非法行为。而这两种入室盗窃行为都没有涉及技术手段。最后一句提到，罪犯使用科技手段来规避安全系统的概率非常小，也就是说只有非常少的一部分入室盗窃是通过技术手段实施的。由此可见，题干是对原文的同义转述，故答案为B，题中Only a very small proportion of burglaries对应原文中的are so small，而 by technical means对应原文中的using technical means。
It is difficult to crack SimpliSafe as its system keeps changing.
注意抓住题干中的关键信息It is difficult to crack SimpliSafe和its system keeps changing。文中段落谈到因为SimpliSafe的系统不断变化所以很难被破解的内容出现在H段，该段前两句提到,我们喜欢这一软件的独特性质。这意味着一个盗贼很可能无法在谷歌上搜索出该系统的运作方式并找出破解它的方法。接下来第三句提到，即使他们可以做到这些，SimpliSafe声称其系统总是会不断发展的，而且每个系统和系统之间也会有细微的差异，这就意味着不会有一个普遍的魔法公式来攻破它。换句话说，由于SimpliSafe的系统是不断变化的，所以要想破解它很难。由此可见，题干是对原文的同义转述，故答案为H。题中It is difficult to crack SimpliSafe对应原文中的there wouldn't be a universal magic formula for cracking it，而 its system keeps changing对应原文中的its system is always evolving。
Wireless devices will transmit signals so as to activate the alarm once something wrong is detected.
注意抓住题干中的关键信息Wireless devices will transmit signals和activate the alarm once something wrong is detected。文中段落论及一旦检测到有什么异常，无线装置将会传输信号以便激活警报器的内容出现在C段，该段首句是主题句，表明了本段的主要内容，即理论上，家庭安全的一个主要问题在于一个给定的系统是否容易被完全封锁。接下来开始具体介绍有线和无线装置的情况。第三和第四句提到，对于无线安全装置来说，你在你家周围安装靠电池供电的传感器以使其对窗户、门、移动装置等进行监控。当这个系统配有防卫装置时，如果它们(靠电池供电的传感器)发现有什么异常,就会向一个基站传输无线警报信号，然后基站就会发出警报。由此可见，题干是对原文的同义转述，故答案为C。题中Wireless devices对应原文中的a wireless setup，而transmit signals so as to activate the alarm once something wrong is detected对应原文中的If they detect something wrong……they'll transmit a wireless alert signal to a base station that will then raise the alarm。
Different measures should be taken to protect one's home from burglary in addition to the wireless security system.
注意抓住题干中的关键信息Different measures should be taken to protect one's home from burglary 。文中段落论及除了无线安全系统外，还应该采取不同的措施来防止人们的住所被盗窃的内容出现在K段，该段第二句提到，它们(这些系统)仅仅是保障你居住安全的一个方面，理想情况下安全应靠多方面的措施来保障，包括常见的诸如声锁和适当的夜间室外照明。由此可见，题干是对原文的同义转述，故答案为K。题中Different measures should be taken to protect one's home from burglary对应原文中的a many-sided approach to securing your home。
SimpliSafe's device can send a warning to the house owner's cellphone.
注意抓住题干中的关键信息SimpliSafe's device和send a warning to the house owner's cellphone。文中段落论及SimpliSafe的装置可以把警报发送到业主的手机上的内容出现在G段，该段第三和第四句提到,然而，我们也验证了SimpliSafe的抗干扰系统是有效的。它把我们抓了个现行，并将警报发送到我的智能手机上，而且还在系统事件日志中列出了我们的射频干扰。由此可见，题干是对原文的同义转述，故答案为G。题中SimpliSafe's device对应原文中的SimpliSafe 's anti-jamming system，而 send a warning to the house owner's cellphone对应原文中的sent an alert to my smartphone。
Burglars can easily get a security device's frequency by Internet search.
注意抓住题干中的关键信息a security device's frequency和Internet search。文中段落论及盗贼们通过网络搜索可以很容易就获得一个安全装置的频率的内容出现在E段，该段第一句提到，安全装置需要列出信号播送频率，这意味着一个潜在的盗贼可以通过最小限度的搜索找到他们需要了解的事情。由此可见，题干是对原文的同义转述,故答案为E。题中burglars can easily get a security device 's frequency对应原文中的a potential thief can find what they need to know，而by Internet search对应原文中的 with minimal Googling。