問題詳情
【題組】45. 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
(E) can be strengthened by the sweetener
參考答案
答案：A
難度：適中0.6
統計：A(3),B(1),C(0),D(0),E(0)