题目内容：
根据材料，完成题。Obesity (肥胖) Causes Global Warming The list of ills attributable to obesity keeps growing: Last week, obese people were accused of causing global warming.
This51comes from Sheldon Jacobson of the University of Illinois, US, and a doctoral student, Laura McLay. Their study 52how much extra gasoline is needed to haul fat Americans around. The answer, they say, is a billion gallons of gas per year.53
There has been54for taxes on junk food in recent years. US economist Martin Schmidt suggests a tax on fast food55to people's cars. "We tax cigarettes partly because of their health cost,”Schmidt said.
"Similarly, leading a lazy life style will end up costing taxpayers more."
US political scientist Eric Oliver said his first instinct was to laugh at these gas and fast food arguments.But such56are getting attention.
At the US Obesity Society’s annual meeting, one person57obesity with car accident deaths,and another correlated obesity with suicides. No one asked whether there was really a cause-and-effect relationship. "The funny thing was that everyone took it59”Oliver said.
In a 1960s study, children were60drawings of children with disabilities and without them, and a drawing of an obese child. They were asked61they would want for a friend? The obese child was picked last.
Three researchers recently repeated the study 62college students. Once again,63no one, not even obese people, liked the obese person. "Obesity was stigmatized." the researchers said.
But, researchers say, getting64is not like quitting smoking. People struggle to stop smoking, and, in the end, many succeed. Obesity is different. Science has shown that they have limited personal control over their weight Genes also65a part.
请在第__(51)__处填上正确答案。 A．study
B．project
C．experiment
D．conclusion
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