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
Coral reefs are one of the most fragile, biologically complex, and diverse marine ecosystem on Earth. This ecosystem is one of t
Coral reefs are one of the most fragile, biologically complex, and diverse marine ecosystem on Earth. This ecosystem is one of t
admin
2014-09-18
45
问题
Coral reefs are one of the most fragile, biologically complex, and diverse marine ecosystem on Earth. This ecosystem is one of the fascinating para- doxes of the biosphere: how do clear, and thus nutrient-poor waters support such prolific and productive communities? Part of the answer lies within the tissues of the corals themselves. Symbi- otic cells of algae known as zooxanthel-lae carry out photosynthesis using the metabolic wastes of the coral thereby producing food tor themselves, for their corals, hosts, and even for other mem- bers of the reef community. This symbiotic process allows organisms in the reef community to use sparse nutrient resources efficiently.
Unfortunately for coral reefs, how- ever, a variety of human activities are causing worldwide degradation of shallow marine habitats by adding nutrients to the water. Agriculture, slash-and-burn land clearing, sewage disposal and manufacturing that creates waste byproducts all increase nutrient loads in these waters. Typical symptoms of reef decline are destabilized herbivore populations and an increasing abundance of algae and filter-feeding animals. Declines in reef communities are consistent with observations that nutrient input is increasing in direct proportion to growing human populations, thereby threat- ening reef communities sensitive to subtle changes in nutrient input to their waters.
According to the passage, which of the following is a factor that is threatening the survival of coral reef communities?
选项
A、The waters they inhabit contain few nutrient resources.
B、A decline in nutrient input is disrupting their symbiotic relationship with zooxanthellae.
C、The degraded waters of their marine habitats have reduced their ability to carry out photosynthesis.
D、They are too biologically complex to survive in habitats with minimal nutrient input.
E、Waste by-products result in an increase in nutrient input to reef communities.
答案
E
解析
哪一个是威胁珊瑚礁群落生存的因素?A.“few nutrient resources”说反了,珊瑚礁就善于在贫营养水体中生存。B.营养减少打乱和动物黄藻的共生关系。无。C.“ability to carry out photosynthesis”文中没说。D.生物上太复杂,不易在贫营养环境中生存。同A,说反了。E.正确。废物副产品导致珊瑚礁群落营养增多。见L23—27。
转载请注明原文地址:https://kaotiyun.com/show/ZgtO777K
本试题收录于:
GMAT VERBAL题库GMAT分类
0
GMAT VERBAL
GMAT
相关试题推荐
Theamountofheatproducedbythiselectricalapparatusis______atwillbyturningasmallhandle.
Normallyastudentmustattendanumberofcoursesinordertograduate,andeachcoursewhichheattendsgiveshimagradewhic
WhentheUnitedStatesCongresscreatedYellowstoneNationalParkin1872,thegoalwastosetasideaplacewhereAmericanscou
Withthepossibleexceptionofequalrights,perhapsthemostcontroversialissueacrosstheUnitedStatestodayisthedeathpe
Packagingisaveryimportantformofadvertising.Apackagecansometimesmotivatepeopletobuyproducts.Forexample,alittl
SpeakerA:Howiseverythinggoingwithyou?SpeakerB:______
Toronto’sthirdCityHall,nowknownasOldCityHall,wasdesignedbyEdwardJamesLennoxanddeclaredopenonSept.18,1899.
WhetheryouarehikingthroughthemagnificentredwoodsofNorthernCalifornia,sleepingunderthebrilliantstarsoftheTexas
Bigdatacanbedefinedasinformationthatistoobigorcomplextobecontainedorprocessedbyanyonemachineorperson.
Ahundredyearsagoitwasassumedandscientifically"proved"byeconomiststhatthelawsofsocietymakeitnecessarytohave
随机试题
地下柔性较大的盐丘受不均衡压力作用而上升,使上覆地层变形,形成背斜圈闭。油气聚集在这样的圈闭中形成的油气藏称为柔性背斜油气藏。()
委员会制又称
汤显祖的《游园》:“袅晴丝吹来闲庭院,__。”
A.麻黄杏仁薏苡甘草汤B.麻黄附子细辛汤C.麻黄附子甘草汤D.麻黄加术汤少阴病,始得之,反发热,脉沉者宜
矩形截面梁高度为h,宽为b,在横力弯曲时切应力的分布规律()。
深厚的湿陷性黄土路基加固,可采用()处理。
老北京的象征建筑物是()。
假定有如下的窗体事件过程:PrivateSubForm_Click()aS="MicrosoftInteger":b$=Right(aS,5)c$=Mid(a$,1,9):MsgBoxaS,34,b$,c$,5
A、 B、 C、 D、 C注意两位男士站在传输带旁的画面。
•YouwillhearpartofaconversationbetweenaninterviewerandAndrewGrove,thechairman,CEOandco-founderofIntel.•For
最新回复
(
0
)