GWD-26 Q9

tlswa

这道题，我能把其余四个都排除，可是还是觉得E选项，说的有点不对。虽然它的主题是在说 pheromones和odorant 的关系。 可是我怎么看了几遍文章，还是觉得 ，作者的观点是说：判断pheromones不属于odorant 的标准，即VNO does process many animal pheromone signals是存在问题的，但是也能说 pheromones should be
                        classified as a type of odorant啦 啊

谢谢指教啊~~

There is no consensus among researchers regarding what qualifies a substance as a pheromone. While most agree on a basic definition of pheromones as chemicals released by one individual of a species which, when detected by another individual of the same species, elicit a specific behavioral or physiological response, some researchers also specify that the response to pheromones must be unconscious. In addition, the distinction between pheromones and odorants— chemicals that are consciously detected as odors---can be blurry, and some researchers classify pheromones as a type of odorant. Evidence that pheromone responses may not involve conscious odor perception comes from the finding that in many species, pheromones are processed by the vomeronasal (or accessory olfactory) system, which uses a special structure in the nose, the vomeronasal organ (VNO), to receive chemical signals. The neural connections between the VNO and the brain are separate from those of the main olfactory system, whose processing of odorants triggers sensations of smell. But while the VNO does process many animal pheromone signals, not all animal pheromones work through the VNO. Conversely, not all chemical signals transmitted via the VNO quality as pheromones. For example, garter snakes detect a chemical signal from earthworms—one of their favorite foods—via the VNO, and they use this signal to track their prey.

Q9

The primary purpose of the passage is to

A.     compare and contrast the ways
                                                    in which the vomeronasal organ
                                                    and the main olfactory systern
                                                    process chemicals.

B.     summarize the debate over the
                                                    role the vomeronasal organ plays in odor perception

C.     present some of the issues
                                                    involved in the debate over
                                                    what constitutes a pheromone

D.     propose a new definition of
                                                    pheromones based on recent
                                                    research

E.     argue that pheromones should be
                                                        classified as a type of odorant

enrique1313

In addition, the distinction between pheromones and odorants— chemicals that are consciously detected as odors---can be blurry, and some researchers classify pheromones as a type of odorant.主旨句，后面就一直在论证

而这句Conversely, not all chemical signals transmitted via the VNO quality as pheromones.仔细一读，就会发现作者的意思就是pheromones should be
                            classified as a type of odorant