阅读理解 The biggest safety threat facing airlines today may not be a man with a gun, but the man with the portable computer in business class. In the last 15 years, pilots have reposed well over 100 incidents that could have been caused by electromagnetic interference(电磁波干扰). The source of this interference remains a mystery, but increasingly, experts are pointing the blame at potable electronic devices such as portable computers, radio and mobile telephones.
RTCA, an organization which advises the aviation(航空)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. 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 predicting how electromagnetic fields might affect an aircraft' s computers. Experts know that portable devices give out radiation that affects navigation and communication of aircraft. 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.
单选题 6.The passage is mainly about______.
【正确答案】 C
【答案解析】文章第一段第一句话“The biggest safety threat facing airlines today may not be a man witha gun，but the man with the portable computer in business class．”指出手提电脑可能给飞机飞行带来最大的安全威胁。故选C。
单选题 7.What is said about the over 100 aircraft incidents in the past 15 years?
【正确答案】 D
【答案解析】由第一段第二句话“In the last 15 years…by electromagnetic interference(电磁波干扰)”可知答案为D。
单选题 8.Few airlines want to impose a total ban on their passengers using electronic devices because
【正确答案】 C
【答案解析】第二段最后一句“Although some airlines prohibit…want to work during flights．”指出大部分航空公司不愿意实行一个全面禁令，原因是很多乘客想在飞行过程中工作。由此可推出，航空公司考虑到这样的禁令可能导致乘客不愿乘坐他们的飞机，故不推行这样的禁令。
单选题 9.Why is it difficult to predict the possible effects of electromagnetic fields on an airplane' s computers?
【正确答案】 C
【答案解析】由第三段最后一句“because they have not been able to reproduce these effects in a labora—tory”可知应选C。
单选题 10.It can be inferred from the passage that the author______.
【正确答案】 C
【答案解析】纵观全文，作者一直强调专家认为电脑可能影响飞机飞行的安全，专家“calling for atotal ban during all flights”，从始至终，作者都没有给出自己的观点，故选C。