英语四级听力难度相对来说比较简答，语速跟VOA慢速英语差不多。为了帮助同学们提高英语四级听力，小编特意整理了2014年12月英语四级听力练习:VOA慢速英语，供各位考生参考，希望大家多多练习。
Welcome to American Mosaic from VOA Learning English. I’m Caty Weaver.
People who steal online information cause billions of dollars in damage every year. These criminals are called “hackers.” The damage would be even greater if there were not security workers who defend computer systems against attacks. Experts say these workers need to know the weaknesses of their systems so they can better-defend them.
Earlier this month, VOA reporter Mike O’Sullivan visited a week-long “hacker” training program in San Diego, California. Young people were being taught how to hack computer systems in order to learn how to fight criminal hackers.
About 20 high school students took part in the five-day-long program. They were among the winners of a local computer competition. Sixteen-year-old Chloe Chrisostomo is one of the students.
“They set networks and we can hack into the network, or we can hack into other people’s computers and then mess with them.”
Students are also being taught about online spying and the sale of stolen information.
This kind of training is important to companies and governments. They want more young people to enter the information security field to help defend against online, or cyber criminals, because attacks are often very costly. Just one successful attack can cost millions of dollars.
It is a problem throughout the world. Police in such countries as India and Romania are having a difficult time fighting cyber criminals.
A recent computer-industry report said attacks on computer systems will cost more than $350 billion this year. Hundreds of billions of dollars will also be spent to stop such attacks.
Trainer Cameron Camp is a security researcher and writer. He says the students are learning how to attack the kinds of computer systems that companies are now using.
“It's set up very similar to what would be a typical corporate environment, so whether you have wi-fi, whether you have corporate networks that store company information, we actually replicate that.”
Jomarri Salomon recently graduated from high school. He says the training helped him understand why computer criminals do what they do.
“To learn how to defend against a hacker, you have to know how a hacker attacks or how a hacker thinks or to be able to defend against that kind of vulnerability that you are probably going to have in the future.”
Mr. Salomon plans to join the U.S. Air Force and work in computer security.
Liz Fraumann works at the nonprofit foundation Securing Our eCity, which helped organize the training. She says students in the program learn a lot more than they think they will.
“When we look at them initially, they think they know it all. They know a lot already. And by Wednesday [they say], ‘I do not know quite as much as I thought.’”
Cameron Camp says he hopes the students will use what they have learned to help, not hurt, computer users.
“And we would like to convince these folks who are skilled computer people that the rewards in the end are much better for working for the good guys rather than the bad guys.”
I’m Caty Weaver. Join us again next week for another American Mosaic from VOA Learning English.
词汇讲解：
1. defend vt. 辩护; 保卫
例句：We must adapt to a changing world, not defend outdated models.
我们必须适应不断变化的世界，而不是捍卫过时的模式。
2. hack vt. 乱劈，乱砍
例句：Can you hack it as a lumber jack?
你当伐木工人可以熬得住吗?
3. attack vt. 攻击，进攻
例句：In colonial days the French armed the Indians to attack the British.
在殖民地时期法国人武装印度人去抗击英国人。
4. graduate vi.渐变; 渐渐变为
例句：I could skip every lecture for a month and still graduate.
我可以一个月不去上课还照样毕业。
5. organize vt. 组织，编组
例句： How do you organize your résumé?
你怎样填写你的简历呢?
6. convince vt.使相信，说服
例句：He tried to convince them of the safety of travelling by airplane.
他想要使他们相信乘飞机旅行的安全。
短语讲解：
1. Young people were being taught how to hack computer systems in order to learn how to fight criminal hackers.
in order to 为了…
例句：He was going for a scholarship in order to go abroad.
为了出国，他准备争取奖学金。
2. About 20 high school students took part in the five-day-long program.
take part in 参加…，参与…活动
例句：Take part in the physical exercises and build up your strength.
参加体育活动增强体力。
3. A recent computer-industry report said attacks on computer systems will cost more than $350 billion this year.
more than 不只是; 很; 超过; 在…次以上
例句：America and britain have more than 12.
美国和英国甚至多余多于12个。
4. “It's set up very similar to what would be a typical corporate environment, so whether you have wi-fi, whether you have corporate networks that store company information, we actually replicate that.”
set up 建立; 准备; 安排; 引起
例句：The students also set up debating teams.
学生们还成立了辩论队。
5. “To learn how to defend against a hacker, you have to know how a hacker attacks or how a hacker thinks or to be able to defend against that kind of vulnerability that you are probably going to have in the future.”
be able to 能，会; 能够
例句：Only then will we be able to design appropriate interactions and interfaces.
只有那时，我们才能够设计合适的交互行为和界面。
6. When we look at them initially, they think they know it all.
look at 看; 评判
例句：She threw a meaningful look at him.
她向他投去意味深长的目光。
7. “And we would like to convince these folks who are skilled computer people that the rewards in the end are much better for working for the good guys rather than the bad guys.”
work for 受雇于; 为…而工作
例句：Comrade Yang will be in charge of that work for the time being.
杨同志将暂时负责那项工作。