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
57
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、specific
B、special
C、specialized
D、especial
答案
C
解析
考查上下文语义衔接和形近词辨析。在这个句子中,and前面说大部分劳动由家庭完成,偶尔使用雇佣劳动,从后面对照的off-farm sources可以推断是没有从外部购买专业化的机器和服务,因此选specialized"专业化的"。specific是"特定的",special"特殊的,特别的",especial是"特别的"。
转载请注明原文地址:https://kaotiyun.com/show/cu44777K
0
考研英语一
相关试题推荐
Aneweconomicspaperhassomeold-fashionedadviceforpeoplenavigatingthestressesoflife:Findaspousewhoisalsoyourb
YawningcanbeaproblemattheofficeforLindsayEierman,whichmakesherembarrassed."I’veexplained,’I’msorry,Ididn’
Writeanessaybasedonthepiechartbelow.Inyourwriting,youshould1)interpretthechart,and2)giveyourcomments.You
Britain’sflexiblelabormarketwasaboonduringtheeconomicrecession,helpingkeepjoblessnessdownandthen,whentherecov
[A]Seekprofessionalhelp[B]Recognizeyourisolation[C]Avoidfallingintothehole[D]TakeaWiFi-freevacatio
[A]Seekprofessionalhelp[B]Recognizeyourisolation[C]Avoidfallingintothehole[D]TakeaWiFi-freevacatio
UncertaintythreatenstheveryexistenceofQuinhagak,Alaska.Thevillageisbuiltonalayerofpermanentlyfrozenground,and
Nameshavegainedincreasingimportanceinthecompetitiveworldofhighereducation.Ascollegesstriveformarketshare,they
随机试题
第一届国际心理卫生大会于_______年在华盛顿召开。
8个月婴儿,因腹泻脱水,测血钠135mmol/L,最适宜补充累积丢失的液体是
支票的㈩票人不得签发与其预留本人的签名式样或者印鉴不符的支票。( )
需求弹性系数是根据需求曲线两个点所代表的价格及相应需求量的变化计算得出的,它代表的是需求曲线上两个点之间的一段弧弹性。()
根据所给材料回答问题。(需计算后回答的问题须列出算式,小数取2位。)某书的正文文字(包括间空)共约35万字。设定开本为A5(即大32开)。正文排版采用15级字,每行排28字,每面排28行,行距为8级。书心用规格为890毫米×1240毫米、定量为7
对一群以前从不吸烟的青少年进行追踪研究,以确定他们是否抽烟及其精神健康状态的变化。一年后,开始吸烟的人患忧郁症的人数是那些不吸烟的人患忧郁症的四倍。因为香烟中的尼古丁令大脑发生化学变化,可能因而影响情绪。所以,吸烟很可能促使青少年患忧郁症。下面哪项如果为真
设A=为A的特征向量.(1)求a,b及A的所有特征值与特征向量;(2)A可否对角化?若可对角化,求可逆矩阵P,使得P-1AP为对角矩阵.
已知Value是一个类,Value是Value的一个对象。下列以非成员函数形式重载的运算符函数原形中,正确的是()。
Humanwantsseemendless.Whenastarvingmangetsameal,hebeginstothinkaboutanovercoat;whenanexecutivegetsanewsp
A、Asingleroomwithoutbathandshower.B、Adoubleroomwithbathandshower.C、Adoubleroomwithoutbathandshower.D、Asing
最新回复
(
0
)