50 Airline: Newly developed collision-avoidance systems, although not fully tested to discover potential malfunctions, must be installed immediately in passenger planes. Their mechanical warnings enable pilots to avoid crashes.

Pilots: Pilots will not fly in planes with collision-avoidance systems that are not fully tested. Malfunctioning systems could mislead pilots, causing crashes.

The pilots’ objection is most strengthened if which of the following is true?

(A) It is always possible for mechanical devices to malfunction.

(B) Jet engines, although not fully tested when first put into use, have achieved exemplary performance and safety records.

(C) Although collision-avoidance systems will enable pilots to avoid some crashes, the likely malfunctions of the not-fully-tested systems will cause even more crashes.

(D) Many airline collisions are caused in part by the exhaustion of overworked pilots. C

(E) Collision-avoidance systems, at this stage of development, appear to have worked better in passenger planes than in cargo planes during experimental flights made over a six-month period.

50.

Choice C states that what the pilots think could happen is likely to happen. Thus, C is the best choice.

Choice A is inappropriate because it says nothing about the malfunctions that most concern the pilots-those that might mislead. Nor does A distinguish tested from not-fully-tested systems.

我的问题是为何A不是支持？

A说是

possible for mechanical devices to malfunction，不就是支持了pilots 吗？

mechanical devices 是否可能 malfunction，与collision-avoidance systems系统无关。或者说与整个话题无关。

有没有collision-avoidance systems，A都成立。

我还是有点想不通。Newly developed collision-avoidance systems　 是　machenical devices 的其中一种呀！

既然　mechenical devices 总是坏，不就是支持了　 collision-avoidance

systems　容易操作失误吗？

还有：

如果是问assumption 这题的A对吗？