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        Scientists have discovered that____ (stay) in the cold could help us lose weight. Researchers at the University of California found that exposure to the cold increases levels of a protein that helps form brown fat—the type of fat that produces heat and keeps us warm. Brown fat burns energy, ____ helps us lose weight. White fat stores extra energy, which results ____ weightgain. The researchers said  that because air conditioning and heating give us constant, ____ (comfort) temperatures, our body's need for brown fat has decreased. They found that:“Outdoor workers in northern Finland who ____ (expose) to cold temperature have ____ significant amount of brown fat when____(compare) to same­ aged indoor workers.”

        The research was conducted on two different control groups of mice. ____group was injected with the protein that helps create brown fat. This group later gained 30% less weight after both groups were fed high­ fat diets.The researchers say this could be good news in the fight against obesity. People who are obese have ____ (low) levels of brown fat than thinnerpeople. Head researcher Hei Sook Sul said: “This protein could become an important target for research into the treatment and prevention of obesity and obesity­ related diseases.” She added：“If you can somehow increase levels of this protein, you could ____(possible) lose more weight even if eating the same amount of food.”