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  3. Normally, seeds of Emmenathe penduliflora stay dormant for years and germina

Normally, seeds of Emmenathe penduliflora stay dormant for years and germina

游客2024-01-10  51
问题     Normally, seeds of Emmenathe penduliflora stay dormant for years and germinate only when a fire burns through their habitat. Nitrogen dioxide in the smoke induces the seeds to germinate. Fires clear the brush, allowing germinating seeds to receive the sunlight they need to grow. The plants mature quickly, produce seeds, and then die. In areas with heavy automobile traffic, however, the seed germinates in the absence of fire, with automobile exhaust supplying the required nitrogen dioxide.
    The information given, if accurate, most strongly supports which of the following hypotheses?
选项 A、Fires in the habitat of E. Penduliflora do not entirely destroy the plant’s seeds even in the places where the fires burn most intensely.
B、The nitrogen dioxide in automobile exhaust cannot harm plants of E. Penduliflora after germination.
C、If human intervention decreases the number of fires in the habitat of E. Penduliflora, automobile exhaust can replicate the conditions the plant requires in order to thrive.
D、Within the habitat of E. Penduliflora, natural fires are significantly more frequent in areas with heavy automobile traffic than they are in other areas.
E、Unless E. Penduliflora seeds that have germinated can survive in the shade, automobile exhaust threatens the long-term survival of the plant in areas with heavy automobile traffic.
答案 E
解析 如果植物能够在阴影环境下生长，那么汽车尾气在促使了植物发芽后，并没有威胁到其生存：如果植物无法在阴影环境下生长，同时交通繁忙的环境无法破坏灌木来为植物提供阳光，那么便是在威胁植物生存，E正确。A项根据原文，因为火会促进种子的萌发，因此火必然没有破坏种子。可是不能证明火烧的最严重的地方都没有破坏种子，不选。而且，火灾破坏种子这件事情是文章之外的信息。B项本文只提到二氧化氮可以促进种子发芽，至于植物发芽后的情况，已经和二氧化氮无关。C项汽车尾气确实可以复制植物的发芽条件，但是植物后期的生长则还要取决于光照条件。不选。D项文章并没有把不同区域的火灾频率进行比较，属于文章以外的信息，不选。
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