GRE Reading Comprehension: JiJing 352-GRE阅读机经352篇 - 485485PL2N1YA02BJ

The primary purpose of the passage is to discuss which of the following? A. reasons for the necessity for developing solar-energy systems B. different ways of storing solar energy as heat C. new designs for devices that collect solar energy D. procedures for transferring thermal energy between materials E. differences between capacities of solids and liquids to store sensible heat