Recently physicians have determined that stomach ulcers are not caused by stress, alcohol, or rich foods, but a bacterium that dwells in the mucous lining of the stomach.
                    
                
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                Anot caused by stress, alcohol, or rich foods, but
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                Bnot caused by stress, alcohol, or rich foods, but are by
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                Ccaused not by stress, alcohol, or rich foods, but by
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                Dcaused not by stress, alcohol, and rich foods, but
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                Ecaused not by stress, alcohol, and rich foods, but are by
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