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Line        Resin is a plant secretion that hardens when
 exposed to air; fossilized resin is called amber.
 Although Pliny in the first century recognized that
 amber was produced from “marrow discharged by
(5)trees,” amber has been widely misunderstood to be
 a semiprecious gem and has even been described
 in mineralogy textbooks. Confusion also persists
 surrounding the term “resin,” which was defined
 before rigorous chemical analyses were available.
(10)Resin is often confused with gum, a substance
 produced in plants in response to bacterial infections,
 and with sap, an aqueous solution transported
 through certain plant tissues. Resin differs from both
 gum and sap in that scientists have not determined a
(15)physiological function for resin.
      In the 1950s, entomologists posited that resin
 may function to repel or attract insects. Fraenkel
 conjectured that plants initially produced resin in
 nonspecific chemical responses to insect attack
(20)and that, over time, plants evolved that produced
 resin with specific repellent effects. But some insect
 species, he noted, might overcome the repellent
 effects, actually becoming attracted to the resin.
 This might induce the insects to feed on those
(25)plants or aid them in securing a breeding site.
 Later researchers suggested that resin mediates
 the complex interdependence, or “coevolution,” of
 plants and insects over time. Such ideas led to the
 development of the specialized discipline of chemical
(30)ecology, which is concerned with the role of plant
 chemicals in interactions with other organisms and
 with the evolution and ecology of plant antiherbivore
 chemistry (plants' chemical defenses against attack
 by herbivores such as insects).


According to the passage, which of the following is true of plant antiherbivore chemistry?
答案:A
问题:搞错定位 选了E 但我想问一下first study和led to development的区别所在。led to development是在这之前没有development的意思吗?我有点混淆了,所以选择了first study。 查看答疑

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