雅思阅读真题（Part 1）
Part 1 · 考频：中频 · 最近考试：2024.5.18/2022.8.11/2020.12.26/2016.1.14/2012.2.18
A
Everyone is familiar with scented flowers, and many people have heard that floral odors help the plant attract pollinators. This common notion is mostly correct, but it is surprising how little scientific proof of it exists. Of course, not all flowers are pollinated by biological agents – for example, many grasses are wind-pollinated – but the flowers of the grasses may still emit volatiles. In fact, plants emit organic molecules all the time, although they may not be obvious to the human nose. As for flower scents that we can detect with our noses, bouquets that attract moths and butterflies generally smell “sweet,” and those that attract certain flies seem “rotten” to us.
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答案：B
原文定位：When the trunk of a pine tree is injured-for example, when a beetle tries to burrow into it-it exudes a very smelly resin;The heavier C20 terpenes, called diterpenes, are glue-like and can cover and immobilize insects as they plug the hole;(Z)-3-hexenyl acetate;deters females of the moth Heliothis virescens from laying eggs on injured tobacco plants;it is the nocturnal blend, rich in several (Z)-3-hexen-1-olesters, that is most effective in repelling the night-active H. virescens moths
答案：spread illness
原文定位：This problem has been exacerbated by recent disease epidemics that have killed many honeybees, the major insect pollinators in the United States
答案：it needs massive manual labour
原文定位：Some growers have attempted to enhance honeybee foraging by spraying scent compounds on orchard trees, but this approach was costly, had to be repeated, had potentially toxic effects on the soil or local biota, and, in the end, proved to be inefficient. The poor effectiveness of this strategy probably reflects inherent limitations of the artificial, topically applied compounds, which clearly fail to convey the appropriate message to the bees
答案：Scent plays a significant role in Ornamental industry.
原文定位：The loss of scent among ornamentals, which have a worldwide value of more than $30 billion, makes them important targets for the genetic manipulation of flower fragrance
答案：Linalool level is too low to be smelt by nose
原文定位：These experiments are still preliminary: For technical reasons, the gene was expressed everywhere in the plant, and although the transgenic plants did create small amounts of linalool, the level was below the threshold of detection for the human nose. Similar experiments in tobacco used genes for other monoterpene synthases, such as the one that produces limonene, but gave similar results
答案：A
原文定位：Everyone is familiar with scented flowers, and many people have heard that floral odors help the plant attract pollinators. This common notion is mostly correct;bouquets that attract moths and butterflies generally smell “sweet,” and those that attract certain flies seem “rotten” to us
答案：F
原文定位：Some work has already begun in this area, as several groups have created petunia and carnation plants that express the linalool synthase gene from C. Breweri;Similar experiments in tobacco used genes for other monoterpene synthases, such as the one that produces limonene, but gave similar results
答案：A
答案：TRUE
原文定位：Everyone is familiar with scented flowers, and many people have heard that floral odors help the plant attract pollinators. This common notion is mostly correct, but it is surprising how little scientific proof of it exists
答案：NOT GIVEN
原文定位：(Z)-3-hexenyl acetate;deters females of the moth Heliothis virescens from laying eggs on injured tobacco plants. Interestingly, the profile of emitted tobacco volatiles is different at night than during the day, and it is the nocturnal blend;that is most effective in repelling the night-active H. virescens moths
答案：TRUE
原文定位：In the rainforest understory tree Leonardoxa Africana, ants of the species Petalomyrmex phylax patrol young leaves and attack any herbivorous insects that they encounter. The young leaves emit high levels of the volatile compound methyl salicylate;It appears that methyl salicylate is both an attractant and a reward offered by the tree to get the ants to perform this valuable deterrent role
答案：FALSE
原文定位：Floral scent has a strong impact on the economic success of many agricultural crops that rely on insect pollinators, including fruit trees such as the bee-pollinated cherry, apple, apricot and peach, as well as vegetables and tropical plants such as papaya. Pollination not only affects crop yield, but also the quality and efficiency of crop production
答案：wasps lay eggs into caterpillars.
原文定位：For example, some parasitic wasps can detect the volatile signature of a damaged plant and will lay their eggs inside the offending caterpillar; eventually, the wasp eggs hatch, and the emerging larvae feed on the caterpillar from the inside out. The growth of infected caterpillars is retarded considerably, to the benefit of the plant