問題詳情

2. Researchers discovered that plants infected with a virus give off a gas that _____ disease resistance inneighboring plants.
(A) advocates
(B) activates
(C) maintains
(D) prescribes

參考答案

答案：B
難度：適中0.5
統計：A(0),B(0),C(0),D(0),E(0)