Ulcers
    1.题目：According to the passage， which of the following is a very likely cause of ulcer in men？
    答案：A）Smoking and stress.
    2.题目：What factors contribute to over half the ulcers？
    答案：C）Environmental factors.
    3.题目：In relation to ulcers， experts study twins in order to examine
    答案：C）the roles of both genetic and environmental factors.
    4.题目：“Environmental effects” in the forth paragraph refers to effects brought about by
    答案：B）smoking and stress in men and use of pain- — Killing medicine in women.
    5.题目：The passage argues that
    答案：B）ulcers are chiefly related to lifestyle.
    速记口诀：
    溃疡
    1.抽烟压力得溃疡____________________
    2.环境加重溃疡病____________________
    3.基因环境均考察____________________
    4.环境乃指烟和药____________________
    5.生活方式惹溃疡____________________