In artificial selection experiments with corn plants that began in the 19th century, scientists have managed to increase oil content of corn kernels by Blank______.Multiple choice question.4.5%4,500%450%100%

Select all that applyThe three main crops that humanity depends upon for food are Blank______.Multiple select question.maize (corn)quinoawheatpotatoesrice

Select all that applyBiofuels are an energy source made from Blank______.Multiple select question.used vegetable oilpetroleumplant materialsanimal fat

Shale oil becomes economically viable at a lower price per barrel of oil than ______.Multiple select question.tar sands oilBrazilian sugar-case-based ethanolbiodieselU.S. corn-based ethanol

Multiple Choice QuestionWhat accounts for 40 percent of the oil consumption in the United States?Multiple choice question.Subway cars and trainsThe production of solar cellsAutomobiles and light trucksLawn mowers and tractors

Multiple Choice QuestionFossil fuels currently account for about Blank______ percent of the world's commercial energy needs.Multiple choice question.8054248