“itself” (linha 5) refere-se a “U.S. Department of Energy”.

“some” (linha 9) refere-se a “oil and natural gas”.

“them” (linha 19) refere-se a “exploration and production technologies”.

“it” (linha 35) refere-se a “new fuel regulations”.

“they” (linha 55) refere-se a “some of our companies”.