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题库 / Prep2008E1-RC-29
Even more than mountainside slides of mud or snow, naturally occurring forest fires promote the survival of aspen trees. Aspens' need for fire may seem illogical since aspens are particularly vulnerable to fires; whereas the bark of most trees consists of dead cells, the aspen's bark is a living, functioning tissue that-along with the rest of the tree-succumbs quickly to fire.
The explanation is that each aspen, while appearing to exist separately as a single tree, is in fact only the stem or shoot of a far larger organism. A group of thousands of aspens can actually constitute a single organism, called a clone, that shares an interconnected root system and a unique set of genes. Thus, when one aspen-a single stem -dies, the entire clone is affected. While alive, a stem sends hormones into the root system to suppress formation of further stems. But when the stem dies, its hormone signal also ceases. If a clone loses many stems simultaneously, the resulting hormonal imbalance triggers a huge increase in new, rapidly growing shoots that can outnumber the ones destroyed. An aspen grove needs to experience fire or some other disturbance regularly, or it will fail to regenerate and spread. Instead, coniferous trees will invade the aspen grove's borders and increasingly block out sunlight needed by the aspens.
It can be inferred from the passage that when aspen groves experience a "disturbance" (see highlighted text), such a disturbance
leads to a hormonal imbalance within an aspen clone
provides soil conditions that are favorable for new shoots
thins out aspen groves that have become overly dense
suppresses the formation of too many new aspen stems
protects aspen groves by primarily destroying coniferous trees rather than aspens
此讲解的内容由AI生成，还未经人工审阅，仅供参考。
正确答案是 C。因为文章中指出，当一个独立的 aspen 树死亡时，整个克隆树的激素信号也会停止。随后，林边的松树会占据 aspen groves 林中的阳光，从而压制 aspens 生长。因此，一个扰动会以减少过度浓密的 aspen groves 为内容，减少新拔立 aspen stems 的数量。
定位: If a clone loses many stems simultaneously, the resulting hormonal imbalance triggers a huge increase in new, rapidly growing shoots tha.
t can outnumber the ones destroyed.
如果有火（或者别的disturbance）这一篇地区的树都会挂，由此带来的imbalance会引发大量新的快速发育的枝芽，并且新芽数量比因为火烧而挂了的还多
其实这个disturbance是刺激杨树细胞生长的，通过产生不平衡的荷尔蒙使杨树产生新细胞。A这个选项乍一眼看上去是一个负面的表达，大家肯定是想找disturbance带给杨树的好处。但是仔细读文章就能发现其实不平衡才会刺激新细胞产生，和文章说的意思一样。
If a clone loses many stems simultaneously, the resulting hormonal imbalance triggers a huge increase in new, rapidly growing shoots that can outnumber the ones destroyed.
If a clone loses many stems simultaneously, the resulting hormonal imbalance triggers a huge increase in new, rapidly growing shoots that can outnumber the ones destroyed.
我以为荷尔蒙失调说一棵树不太好，其实原话就是这么说的
排除e，火灾会烧coniferous trees & aspens是对的，但没讲先后之分，先烧aspens也是可能的，因为文章最开始说了它对火屈服快
文章的意思是说一个死的话 会停止荷尔蒙信号，但是如果很多一起死了，imbalance就会导致长出来很多超过原来死掉的。所以这种树需要经历火灾或者别的disturbance（让很多stem死 这样才能产生更多的）来让这种书regenerate
But when the stem dies, its hormone signal also ceases. If a clone loses many stems simultaneously, the resulting hormonal imbalance triggers a huge increase in new, rapidly growing shoots that can outnumber the ones destroyed.
While alive, a stem sends hormones>> suppress formation of further stems.
But when the stem dies, its hormone signal also ceases>> resulting hormonal imbalance triggers a huge increase in new,
所以火可以抑制 hormonal imbalance ，避免過多成長
But when the stem dies, its hormone signal also ceases. If a clone loses many stems simultaneously, the resulting hormonal imbalance triggers a huge increase in new, rapidly growing shoots that can outnumber the ones destroyed.
定位句：If a clone loses many stems simultaneously, the resulting hormonal imbalance triggers a huge increase in new, rapidly growing shoots that can outnumber the ones destroyed.
If a clone loses many stems simultaneously, the resulting hormonal imbalance triggers a huge increase in new, rapidly growing shoots that can outnumber the ones destroyed. An aspen grove needs to experience fire or some other disturbance regularly, or it will fail to regenerate and spread. Instead, coniferous trees will invade the aspen grove's borders and increasingly block out sunlight needed by the aspens.
是a不是d
读懂搞定一切
disturb=lose stems----inbalance----regenerate
读懂文章太太太重要了
stems 同时死掉=disturbance
答案应该是A吧，cd论坛上搜这道题是A，别的网站上搜这道题答案也是A
答案应该是D