أرسل هذا في رسالة قصيرة: Cost-benefit analysis of energy efficiency system for homes and buildings

            ______   ______     _____    ______   
    ___    /_   _// |      \\  |  ___|| |      \\ 
   /   ||   -| ||-  |  --  //  | ||__   |  --  // 
  | [] ||   _| ||_  |  --  \\  | ||__   |  --  \\ 
   \__ ||  /_____// |______//  |_____|| |______// 
    -|_||  `-----`  `------`   `-----`  `------`  
     `-`