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 devices such as portable computers, radio and cassette players and mobile telephones.
RTCA, an organization which advises the aviation industry, has recommended that all airlines ban 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 devices 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 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.
1.The passage is mainly about（ ） .
2.What is said about the over 100 aircraft incidents in the past 15 years?
3.Few airlines want to impose a total ban on their passengers using electronic devices because（ ）
4.Why is it difficult to predict the possible effects of electromagnetic fields on an airplane’s computers?
5.It can be inferred from the passage that the author（ ） .
问题1选项
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
问题2选项
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
问题3选项
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
问题4选项
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 that same effects in labs
D.Because experts lack adequate equipment to do such research
问题5选项
A.is in favor of prohibiting passenger’ 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
第1题:C
第2题:D
第3题:C
第4题:C
第5题:A
1.主旨大意题。文章开篇第一句话点明主旨: 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(如今航空公司面临的最大的安全威胁可能不是持枪的恐怖分子，而是商务舱里带着便携式电脑的乘客)。故选C。
2.细节事实。根据题干定位至第一段: In the last 15 years, pilots have reported well over 100 incidents that could have been caused by electromagnetic interference (在过去的15年中，飞行员报告说100多起事故可能由电磁干扰引起的)。
3.细节事实。根据题干定位至第二段: most are reluctant to enforce a total ban, given that many passengers want to work during flights(由于许多乘客想在飞行期间工作，多数航空公司不愿意执行全面禁令)。
4.细节事实。第三段给出了原因: 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. (由于他们无法在实验室中重现这些效应，他们无法知道干扰是否有危险)。
5.观点态度。根据文章大意，可以看出作者的态度。
