1.      Modern navigation systems, which are found in most of today’s commercial aircraft, are made with low-power circuitry, which is more susceptible to interference than the vacuum-tube circuitry found in older planes. During landing, navigation systems receive radio signals from the airport to guide the plane to the runway. Recently, one plane with low-power circuitry veered off course during landing, its dials dimming, when a passenger turned on a laptop computer. Clearly, modern aircraft navigation systems are being put at risk by the electronic devices that passengers carry on board, such as cassette players and laptop computers.
Which one of the following, if true, LEAST strengthens the argument above?

(A) After the laptop computer was turned off, the plane regained course and its navigation instruments and dials returned to normal.
(B) When in use all electronic devices emit electromagnetic radiation, which is known to interfere with circuitry.
(C) No problems with navigational equipment or instrument dials have been reported on flights with no passenger-owned electronic devices on board.
(D) Significant electromagnetic radiation from portable electronic devices can travel up to eight meters, and some passenger seats on modern aircraft are located within four meters of the navigation systems.
(E) Planes were first equipped with low-power circuitry at about the same time portable electronic devices became popular.

选什么？  该怎么想？

选什么？  该怎么想？

我觉得是b

b只说了所有电子设备都有辐射，但是没有说辐射是否足够影响飞机电路，所以比较象无关选项

e说明了便携式电子设备流行，流行必然造成乘客带上飞机是会经常发生的，影响飞机电路也是经常发生的，所以risky

我觉得应该选e,其他都加强了全文的观点，I.E.'Clearly, modern aircraft

navigation systems are being put at risk by the electronic devices that

passengers carry on board, such as cassette players and laptop computers'。

我也觉得是E

同时发生的事情未必相关，就像两件事情一先一后也未必就有因果联系