<prompt> Translate the following text to EnglishSeneta Jeffords na Lieberman waliomba Shirika la Ulinzi wa Mazingira EPA kufanya tathmini ya kiuchumi ya hali nne za teknolojia zilizopangwa kufikia viwango vya chini vya uzalishaji katika sekta ya umeme ya Marekani ifikapo mwaka 2007.  <response>: In their request, Senators Jeffords and Lieberman asked the Environmental Protection Agency to undertake an economic assessment of four technology-based scenarios designed to achieve the following emissions caps in the US electric power sector by the year 2007: 