首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Mycorrhizal fungi infect more plants than do any other fungi and are necessary for many plants to thrive, but they have escaped
Mycorrhizal fungi infect more plants than do any other fungi and are necessary for many plants to thrive, but they have escaped
admin
2011-01-26
45
问题
Mycorrhizal fungi infect more plants than do any other fungi and are necessary for many plants to thrive, but they have escaped widespread investigation until recently for two reasons. First, the symbiotic association is so well-balanced that the roots of host plants show no damage even when densely infected. Second, the fungi cannot as yet be cultivated in the absence of a living root. De spite these difficulties, there has been important new work that suggests that this symbiotic association can be harnessed to achieve more economical use of costly super phosphate fertilizer and to permit better exploitation of cheaper, less soluble rock phosphate, Mycorrhizal benefits are not limited to improved phosphate uptake in host plants. In legumes, mycorrhzal inoculation has increased nitrogen fixation beyond levels achieved by adding phosphate fertilizer alone. Certain symbiotic associations also increase the host plant’ s resistance to harmful root fungi. Whether this resistance results from exclusion of harmful fungi through competition for sites, from metabolic change involving antibiotic production, or from increased vigor is undetermined.
Which of the following most accurately describes the passage?
选项
A、A description of a replicable experiment
B、A refutation of an earlier hypothesis
C、A summary report of new findings
D、A confirmation of earlier research
答案
C
解析
综观全文,以及文章开头提到的“but they have escaped widespread investigation until recently”可知这是对一个科学新发现的阐述。A项“对可重复实验的描述”,B项“对假设的批驳”,D项“对早期研究的确认”均不对。
转载请注明原文地址:https://kaotiyun.com/show/Y9BO777K
0
考博英语
相关试题推荐
Youwillhearaconversationthroughaphone.Foreachquestion(23-30),markoneletter(A,BorC)forthecorrectanswer.After
Youwillhearaconversationthroughaphone.Foreachquestion(23-30),markoneletter(A,BorC)forthecorrectanswer.After
Lookattheformbelow.Someinformationismissing.Youwillhearawomanbookingexhibitionspaceonthephone.Foreachquest
Lookattheformbelow.Someinformationismissing.Youwillhearawomanbookingexhibitionspaceonthephone.Foreachquest
•Readthearticlebelowaboutworkingindifferentsizedcompanies.•Aresentences16-22ontheoppositepage’Right’or’Wrong’
•Readthearticlebelowaboutworkingindifferentsizedcompanies.•Aresentences16-22ontheoppositepage’Right’or’Wrong’
•Readthearticlebelowaboutworkingindifferentsizedcompanies.•Aresentences16-22ontheoppositepage’Right’or’Wrong’
随机试题
原发综合征
治疗肺阴亏损肺痨,宜选用治疗肺阴亏损虚劳,宜选用
深感觉包括()
天线应该在避雷针()保护范围内。
秘书应掌握的手工文字记录方法有()。
我国的国家结构形式属于()。
对城市建设焕然一新的追求,不仅会使城市记忆受到损坏甚至毁灭,也是对城市中人的生活情感的______。城市中长期积淀形成的文化风格和人文环境,被当作了“过时”的东西予以______或抛弃,城市记忆也因此没有了依托对象,公众的情感认同无法被唤起,在心灵上就会出
[2007年]设三阶实对称矩阵A的特征值λ1=1,λ2=2,λ3=-2,α1=[1,-1,1]T是A的属于λ1的一个特征向量.记B=A5-4A3+E,其中E为三阶单位矩阵.验证α1是矩阵B的特征向量,并求B的全部特征值与特征向量;
设n阶方程A=(α1,α2,…,αn),B=(β1,β2,…,βn),AB=(γ1,γ2,…γn),记向量组(I):1,α2,…,αn,(Ⅱ):β1,β2,…,βn,(Ⅲ):γ1,γ2,…γn,如果向量组(Ⅲ)线性相关,则().
Windows98中,可以打开“开始”菜单的组合键是()。
最新回复
(
0
)