42. The purpose of the second mention of "hormones" in line 4 is to point out
(A) chemical signals that are common among insects
(B) specific responses of various species to chemical signals
(C) similarities between two chemical substances
(D) how insects produce different chemical substances
43. The word "sole" in line 6 is closest in meaning to
(A) obvious
(B) best
(C) only
(D) final
44. The passage suggests that the speed at which communication through pheromones occurs is dependent on how quickly they
(A) lose their effectiveness
(B) evaporate in the air
(C) travel through the air中 华 考 试 网
(D) are produced by the body
45. According to the passage, the meaning of a message communicated through a
pheromone may vary when the
(A) chemical structure of the pheromone is changed
(B) pheromone is excreted while other pheromones are also being excreted
(C) exocrine glands do not produce the pheromone
(D) pheromone is released near certain specific organisms
46. The word "detecting" in line 23 is closest in meaning to
(A) controlling
(B) storing
(C) questioning
(D) finding