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
Where Have All the Bees Gone? Scientists who study insects have a real mystery on their hands. All across the country, honey
Where Have All the Bees Gone? Scientists who study insects have a real mystery on their hands. All across the country, honey
admin
2013-10-25
91
问题
Where Have All the Bees Gone?
Scientists who study insects have a real mystery on their hands. All across the country, honeybees are leaving their hives and never returning. Researchers call this phenomenon colony-collapse disorder. According to surveys of bee keepers across the country, 25 to 40 percent of the honeybees in the United States have vanished from their hives since last fall. So far, no one can explain why.
Colony collapse is a serious concern because bees play an important role in the production of about one-third of the foods we eat. As they feed, honeybees spread pollen from flower to flower. Without this process, a plant can’t produce seeds or fruits.
Now, a group of scientists and beekeepers have teamed up to try to figure out what’s causing the alarming collapse of so many colonies. By sharing their expertise in honeybee behavior, health, and nutrition, team members hope to find out what’s contributing to the decline and to prevent bee disappearance in the future.
It could be that disease is causing the disappearance of the bees. To explore that possibility, Jay Evans, a researcher at the United States Department of Agriculture(USDA)Bee Research Laboratory, examines bees taken from colonies that are collapsing. "We know what a healthy bee should look like on the inside, and we can look for physical signs of disease, " he says. And bees from collapsing colonies don’t look very healthy. "Their stomachs are worn down, compared to the stomachs of healthy bees, " Evans says. It may be that a parasite is damaging the bees digestive organs. Their immune systems may not be working as they should. Moreover, they have high levels of bacteria inside their bodies.
Another cause of colony-collapse disorder may be certain chemicals that farmers apply to kill unwanted insects on crops, says Jerry Hayes, chief bee inspector for the Florida Department of Agriculture. Some studies, he says, suggest that a certain type of insecticide affects the honeybee’s nervous system(which includes the brain)and memory. "It seems like honeybees are going out and getting confused about where to go and what to do, " he says.
If it turns out that a disease is contributing to colony collapse, bees genes could explain why some colonies have collapsed and others have not. In any group of bees there are many different kinds of genes. The more different genes a group has, the higher the group’s genetic diversity. So far scientists haven’t determined the role of genetic diversity in colony collapse, but it’s a promising theory, says Evans.
What are the possible causes of colony-collapsedisorder given by the scientists?
选项
A、Worsening environment.
B、Diseaseand chemicals.
C、Dwindling number of flowers around.
D、Changes ingenes’ structures.
答案
B
解析
转载请注明原文地址:https://kaotiyun.com/show/gXmd777K
本试题收录于:
职称英语卫生类B级题库职称英语分类
0
职称英语卫生类B级
职称英语
相关试题推荐
Readthefollowingmagazinearticleandanswerquestions9-18onthenextpage.TheBurdenofThirst0
Youwillhearfivepeoplegivingtheiropinionsonspankingchildren.Forquestions9-13,choosefromthelistA-Fwhateac
Youwillhearfivepeoplegivingtheiropinionsonspankingchildren.Forquestions9-13,choosefromthelistA-Fwhateac
CONVERSATION2(Questions5-8)MESSAGEProblem:Therewasa【L5】______problem.Mr.Franks’companyha
DEALINGWITHWASTEPLASTICEveryyearpeoplethrowawaymillionsoftonnesofplasticbottles,boxesandwrapping.Thesecr
DEALINGWITHWASTEPLASTICEveryyearpeoplethrowawaymillionsoftonnesofplasticbottles,boxesandwrapping.Thesecr
Johnwas(irritated)bythenecessityforpoliteconversation.
CellPhones:HangUporKeepTalking?Millionsofpeopleareusingcellphonestoday.Inmanyplacesitisactuallyconsider
WaterFromthebeginning,waterhasfurnishedmanwithasourceoffoodandahighwaytotravelupon.Thefirst(51)arosewhere
Babies’ResponseForsometimeinthepastithasbeenwidelyacceptedthatbabies,andothercreatureslearntodothingsb
随机试题
“收入一费用=利润”这一会计等式,是复式记账法的理论基础,也是编制资产负债表的依据。()
工资和福利费属于单位()核算内容。
采用支付手续费委托代销方式销售商品时,委托方发出商品涉及的会计科目有()。
按照能否恢复分类,海洋资源可分为()。
设函数f(x)在(-∞,+∞)内连续,其导函数的图形如图所示,则f(x)有
关于宇宙起源的科学发现——1998年英译汉及详解Theywere,byfar,thelargestandmostdistantobjectsthatscientistshadeverdetected:astripof
文件的扩展名可以说明文件类型。下面的“文件类型一扩展名”对应关系错误的是:
软件的何种性能是指软件只允许被授权用户使用(包括读、写、打印、浏览等)?(64)。
A、Preference.B、Something.C、Problem.D、Lesson.C细节题。文中提到,一些不够积极的词语不建议在申请信中使用,如“惊慌”、“问题”、“可怕”,C)为其中一项,故为答案。
GPSA)TheGlobalPositioningSystemisa.space-basedtriangulationsystemusingsatellitesandcomputerstomeasurepositi
最新回复
(
0
)