11.Laudenslager's experiment showed that the immune system of those rats who could turn off the electricity ______ .
A) was strengthened
B) was not affected
C) was altered
D)was weakened
l2.According to the passage, the experience of helplessness causes rats to_________ .
A) try to control unpleasant stimuli
B) turn off the electricity
C) behave passively in controllable
situations
D) become abnormally suspicious
13.The reason why the mice in Ader's experiment avoided saccharin was that ________ .
A)they disliked its taste
B)it affected their immune systems
C)it led to stomach pains
D)they associated it with stomachaches
l4.The passage tells us that the most probable reason for the death of the mice in Ader's experiment was that_____ .
A)they had been weakened psychologically by the saccharin
B)the sweetener was poisonous to them
C)their immune systems had been altered by the mind
D)they had taken too much sweetener during earlier conditioning
15.It can be concluded from the passage that the immune systems of animals __________ .
A)can be weakened by conditioning
B)can be suppressed by drug injections
C)can be affected by frequent doses of saccharin
D)can be altered by electric shocks
答案:Passage 1 : CDABC
Passage 2: CDDBA
Passage 3: BADAC
Passage 4: BCDCB
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