请大家试着翻译文章中划线句子。
terrorist n.恐怖分子 terrorism n.恐怖主义，恐怖手段 terror n.恐怖惊骇；恐怖的事
interference n.干涉，妨碍；干扰 interfere v.干涉，介入，干预； interfering a.好干涉的，爱管闲事的
currently adv.当前，时下
navigation n.航海，航空，驾驶；航海术，航空术
defect n.缺点，不足之处，毛病，瑕疵；v.背叛

Passage One
Questions 21 to 25 are based on the following passage:

　　The biggest safety threat facing airlines today may not be a terrorist with a gun, but the man with the portable computer in business class. In the last 15 years, pilots have reported well over 100 incidents that could have been caused by electromagnetic interference. The source of this interference remains unconfirmed, but increasingly, experts are pointing the blame at portable electronic device such as portable computers, radio and cassette players and mobile telephones.　　
　　RTCA, an organization which advises the aviation（航空）industry, has recommended that all airlines ban（禁止）such devices from being used during “critical” stages of flight, particularly take-off and landing. Some experts have gone further, calling for a total ban during all flights. Currently, rules on using these devices are left up to individual airlines. And although some airlines prohibit passengers from using such equipment during take-off and landing, most are reluctant to enforce a total ban, given that many passengers want to work during flights.
　　The difficulty is predicting how electromagnetic fields might affect an aircraft’s computers. Experts know that portable device emit radiation which affects those wavelengths which aircraft use for navigation and communication. But, because they have not been able to reproduce these effects in a laboratory, they have no way of knowing whether the interference might be dangerous or not.
　　The fact that aircraft may be vulnerable（易受损的）to interference raises the risk that terrorists may use radio systems in order to damage navigation equipment. As worrying, though, is the passenger who can’t hear the instructions to turn off his radio because the music’s too loud.

21.The passage is mainly about ___________.
　　A) a new regulation for all airlines
　　B) the defects of electronic devices
　　C) a possible cause of aircraft crashes
　　D) effective safety measures for air flight

22.What is said about the over 100 aircraft incidents in the past 15 years?
　　A) They may have been caused by the damage to the radio systems.
　　B) They may have taken place during take-off and landing.
　　C) They were proved to have been caused by the passengers’ portable computers.
　　D) They were suspected to have resulted from electromagnetic interference.

23.Few airlines want to impose a total ban on their passengers using electronic devices because __________.

A) they don’t believe there is such a danger as radio interference
　　B) the harmful effect of electromagnetic interference is yet to be proved
　　C) most passengers refuse to take a plane which bans the use of radio and cassette players
　　D) they have other effective safety measures to fall back on

24.Why is it difficult to predict the possible effects of electromagnetic fields on an airplane’s computers?
　　A) Because it is extremely dangerous to conduct such research on an airplane.
　　B) Because it remains a mystery what wavelengths are liable to be interfered with.
　　C) Because research scientists have not been able to produce the same effects in labs.
　　D) Because experts lack adequate equipment to do such research.

25.It can be inferred from the passage that the author ___________.
　　A) is in favor of prohibiting passengers’ use of electronic devices completely
　　B) has overestimated the danger of electromagnetic interference
　　C) hasn’t formed his own opinion on this problem
　　D) regards it as unreasonable to exercise a total ban during flight

答案
翻译：这种干扰源尚未最后确定，但是专家们越来越多的指责便携式电脑、收音机、录音机、移动电话等电子设备。
　　这句话里面的but increasingly,我觉得值得记住，很多同学写作文的时候喜欢用more and more people…，用的人多了就没有新意了，换成people in increasing numbers…或者the growing number of people…或者文中这样的形式就容易给阅卷老师一个好的印象。
　　先大概看一下题干，21是主题题，25是态度题，中间3个是细节题。文章有4段，按顺序来找答案。
　　21.主题一般在第一段段首。如果这个题出现在中间的话，一般对应某一段的内容和主题，范围小一点，比较容易。如果是第1题或最后一题，则对应整篇文章。我们可以把这个题放一放，最后来做。
　　22.题干有数字，很容易在文中第一段找到对应的句子。注意could，表示可能 所以选D：怀疑他们是电磁干扰的结果。A中the radio systems过于细节，此段没有提到。B此段也没有提到。D出现在列举里面，而且前提是unconfirmed。
　　23.关键句在二段最后一句，given that many passengers want to work during flights. 很多乘客要在飞行期间工作，可以推断他们拒绝禁令（真是要工作不要命）选C。
　　24.三段because 后面给出了解释：因为他们不能在实验室重现这些影响，所以他们没办法知道干扰是不是有危险。所以选C。A文中没有说过，B和第二句相反，D没有提到
　　25.作者没有很明确的态度，只是做客观的说明，描写了很多情况，但没有表明自己的立场和看法。A赞成禁令；B高估危险；C没有形成自己的观点；D认为禁令无理。应该选C。
　　再看21题，本文的主题是关于说电磁干扰可能影响飞机安全。选C。A新的航线规章；B电子设备的缺点；C一个可能引起飞机坠落的原因；D飞行的安全措施。
　　文章第一段给出主题，也给出了21、22的答案，23题答案在二段，24题答案在三段，25题也可以从前面得出答案。四段句子又长又复杂，但是我们看一个题干找一个答案，前三段已经提供了足够的信息。所以考试的时候四段可以快速扫过甚至不看.