OG6 阅读 Q45

Choice C is the best answer. It can reasonably be inferred that much of the solar panel industry believes current solar technology is too expensive and inefficient because the passage states that the industry has been working to improve those two things: "All parts of the silicon solar panel industry have been looking for ways to cut costs and improve the power output of solar panels, and that's led to steady cost reductions" (lines 27-30). 
Choice A is incorrect because the passage explains how solar panels work but never states or implies that consumers do not understand the technology. Choice B is incorrect because while the passage explains how two-sided solar cells can increase solar electric output, it does not suggest that they have any existing or possible weaknesses. Choice D is incorrect because the passage characterizes Willow Glass as entirely promising and doesn't imply that it is not efficient enough to be marketed.