4.2+peroid+3

=  Cabral, Elena. "Packing a Punch." __Scholastic News__ 10 Sept. 2007. = = __eLibrary__. ProQuest. Hempfield High School Lib., Landisville, PA. 10 = =    = =   May 2008 <[|http://elibrary.bigchalk.com/>.]   = = __ Deadly droughts __. DK Eyewitness Hurricane, 2004. __eLibrary__. ProQuest. = =    = =   Hempfield High School Lib., Landisville, PA. 18 Apr. 2008   = =  = =  [|http://elibrary.bigchalk.com/   = =    = =     = =     = =     = =   "Energy Efficiency." __Energy Kid's Page__. Energy Information  = =    = =   Administration. 30 Apr. 2008   = =    = =   <     http://www.eia.doe.gov/kids/energyfacts/saving/efficiency/   = =  savingenergy.html>. = = __ Environment of Planet Earth __. Eco-Pros. 22 Apr. 2008 <[|http://www.eco]-  = =    = =   pros.com/index.htm>. = = = = Tornado. Newfield Publications, 1996. __eLibrary__. ProQuest. Hempfield = = = =  High School Lib., Landisville, PA. 21 Apr. 2008   = =    = =   . = =    = =     = =     = =     = =   "United States of America: Natural Resources and Industry." __Countries of__  = =  = =  __the__ __World__. Bureau of Electronic Publishing, 1991. __eLibrary__. = =  ProQuest. Hempfield High School Lib., Landisville, PA. 11 May 2008  = =    = =   <[|http://elibrary.bigchalk.com/> .]   =