3. In relation to ulcers, experts study twins in order to examine
A) the roles of genetic factors.
B) the roles of environmental factors.
C) the roles of both factors.
D) the roles of brotherhood.
4. What does "environmental effects" in the fifth paragraph refer to?
A) A clean environment with no smoke and dust surrounding the living area.
B) Smoking and stress in men and use of pain-killing medicine in Women.
C) Factors shared by family members such as genes and the food they eat.
D) Shared exposure to H. pylori infection in the unclean environment.
5. The passage argues that
A) ulcers are related to genes.
B) ulcers are related to lifestyle.
C) ulcers appear in men and women.
D) ulcers are caused by pylori infection.
KEY: ACCBB
A) the roles of genetic factors.
B) the roles of environmental factors.
C) the roles of both factors.
D) the roles of brotherhood.
4. What does "environmental effects" in the fifth paragraph refer to?
A) A clean environment with no smoke and dust surrounding the living area.
B) Smoking and stress in men and use of pain-killing medicine in Women.
C) Factors shared by family members such as genes and the food they eat.
D) Shared exposure to H. pylori infection in the unclean environment.
5. The passage argues that
A) ulcers are related to genes.
B) ulcers are related to lifestyle.
C) ulcers appear in men and women.
D) ulcers are caused by pylori infection.
KEY: ACCBB