Even though ulcers appear to run in families, lifestyle plays more of a role than genetic factors in causing the illness, according to a report in the April 13th Journal of Internal Medicine. In particular, smoking and stress in men and the regular use of pain-releasing medicines in women were linked with an increased risk of developing an ulcer.　　Raiha and colleagues studied data from more than 13,000 pairs of twins to examine the roles of genetic and environmental factors in the origin of peptic ulcer disease, they explain. Both twins were more likely to develop an ulcer if the pair were genetically the same as compared with a pair of fraternal twins, suggesting that there must be some genetic susceptibility to ulcer development.　　1. According to the passage, which of the following is a very likely cause of ulcer in men?　　B) Drinking and smoking.　　D) Use of a certain medicine.　　A) Hereditary factors.　　C) Environmental factors.　　3. In relation to ulcers, experts study twins in order to examine　　B) the roles of environmental factors.　　D) the roles of brotherhood.　　A) A clean environment with no smoke and dust surrounding the living area.　　C) Factors shared by family members such as genes and the food they eat.　　5. The passage argues that　　B) ulcers are related to lifestyle.　　D) ulcers are caused by pylori infection.