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
考研
Until about four decades ago, crop yields in agricultural systems depended on (1)_____ resources, recycling organic matter, buil
Until about four decades ago, crop yields in agricultural systems depended on (1)_____ resources, recycling organic matter, buil
admin
2010-06-17
41
问题
Until about four decades ago, crop yields in agricultural systems depended on (1)_____ resources, recycling organic matter, built-in biological control mechanisms and rainfall patterns. Agricultural yields were (2)_____ but stable. Production was (3)_____ by growing more than one crop or variety in space and time in a field as insurance against pest (4)_____ or severe weather. Inputs of nitrogen were (5)_____ by rotating major field crops with legumes. In turn, rotations suppressed insects, weeds and diseases by effectively (6)_____ the life cycles of these pests. A typical corn belt farmer grew corn (7)_____ with several crops including soybeans, and small grain production was intrinsic to maintain livestock. Most of the labor was done by the family with occasional hired help and no (8)_____ equipment or services were purchased from off4arm sources. In these type of farming systems the link between agriculture and ecology was quite (9)_____ and signs of environment degradation were seldom evident.
But as agriculture modernization (10)_____ the ecology-farming linkage was often broken as ecological principles were (11)_____. In fact, several agricultural scientists have arrived at a (12)_____ consensus that modem agriculture confronts an environment crisis. A growing number of people have become concerned about the long-term (13)_____ of existing food production systems. Evidence has shown that (14)_____ the present capital-and-technology-intensive fanning systems have been extremely productive and competitive, they also bring a (15)_____ of economic, environmental and social problems.
Evidence also shows that the very nature of the agricultural structure and prevailing polices have led to this environmental (16)_____ by favoring large farm size, specialized production, crop monocultures and mechanization. Today as more and more farmers are integrated (17)_____ international economies, imperatives to (18)_____ disappear and monocultures are rewarded by economies of scale. In turn, lack of rotations and diversification (19)_____ key self-regulating mechanisms, turning monocultures into highly (20)_____ agro-ecosystems dependent on high chemical inputs.
选项
A、safeguarded
B、ensured
C、hindered
D、disturbed
答案
A
解析
考查上下文语义衔接。后面已经有提示as insurance,既然是作为保险,前面肯定要填一个同义的动词作谓语,意思是产量受到保护,safeguard是"保护…免受伤害",符合文章的意思;ensure一般指确保某事发生;hinder是"阻碍",disturb是"打扰",都不符合文章意思。
转载请注明原文地址:https://jikaoti.com/ti/uwRRFFFM
0
考研英语一
相关试题推荐
Aneweconomicspaperhassomeold-fashionedadviceforpeoplenavigatingthestressesoflife:Findaspousewhoisalsoyourb
Aneweconomicspaperhassomeold-fashionedadviceforpeoplenavigatingthestressesoflife:Findaspousewhoisalsoyourb
YawningcanbeaproblemattheofficeforLindsayEierman,whichmakesherembarrassed."I’veexplained,’I’msorry,Ididn’
Howbesttosolvethepollutionproblemsofacitysunksodeepwithinsulfurouscloudsthatitwasdescribedashellonearth?
WhentheislandofSingaporebecameanindependentcountryin1965,ithadfewfriendsandevenfewernaturalresources.Howdid
Earlierthismonth,researcherBeaverofFloridaStateUniversityreportedthatheandhisco-authorshadidentifiedgeneticmar
[A]Seekprofessionalhelp[B]Recognizeyourisolation[C]Avoidfallingintothehole[D]TakeaWiFi-freevacatio
Fromthepassagewelearnthat______.Thesentence"Thisisnoflashinthepan"(Line5,Paragraph3)meansthat______.
Ashumanchildrenareunusuallydependentfaranunusuallylongtime,it’sobviousthateverysocietymustprovideadomesticco
Ashumanchildrenareunusuallydependentfaranunusuallylongtime,it’sobviousthateverysocietymustprovideadomesticco
随机试题
按照电流转换成作用于人体的能量的不同形式,电伤分为电弧烧伤、电流灼伤、皮肤金属化、电烙印、电气机械性伤害、电光眼等类别。下列关于电伤情景及电伤类别的说法中,正确的有()。
内服能活血散瘀止痛,外用可止血生肌敛疮的药为
哪项不是可摘局部义齿基托的主要功能
关于民用建筑工程室内环境检测的说法,正确的有()。
( )构成依法治税的基本内容。
下列各项中,应当计入房产税计税原值的有()。
幼儿一般每顿饭的进餐时间约________分钟为宜。
政府在社会管理方面的基本职能就是向社会提供()。
设函数f(x)=|tx一x2|dt(x>0),求f(x)并求f(x)的最小值.
信息系统是由硬件、软件、数据库、远程通信和网络、人员以及过程组成的。其中起主导作用的是()。
最新回复
(
0
)