题目内容：
阅读材料，回答题。All the useful energy at the surface of the earth comes fromthe activity of the sun. The sun heats and feeds creatures and mankind. Eachyear it provides men with two hundred million tons of grain and nearly tenmillion tons of wood, coal, oil, natural gas, and all other fuels are stored energyfrom the sun. Some was collected by this season’s plants as carbon compounds.Some was stored by plants and trees ages ago. Even waterpower derives from thesun. Water turned into vapor by the sun fails as rain. It courses down themountains and is converted to electric power. Light transmits only the energythat comes from the sun’s outer layer, and much of this energy that is directedtowards the earth never arrives. About nine tenths of it is absorbed by theatmosphere of the earth. In fact, the earth itself gets only one half millionthof the sun's entire output of radiant energy.
The sun is the source of all of the following EXCEPT ________ A．gasoline
B．natural gas
C．atomic power
D．animal fat
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