40. What does the passage mainly discuss?
(A) How insects use pheromones to communicate
(B) How pheromones are produced by insects
(C) Why analyzing insect pheromones is difficult
(D) The different uses of pheromones among various insect species
答案:登入後查看
統計: A(1), B(0), C(0), D(0), E(0) #802163
統計: A(1), B(0), C(0), D(0), E(0) #802163