首页
登录
职称英语
Naturalists and casual observers alike have been struck by the special r
Naturalists and casual observers alike have been struck by the special r
游客
2024-01-05
76
管理
问题
Naturalists and casual observers alike have been struck by the special relationship
between squirrels and acorns (the seeds of oak trees). Ecologists, though, cannot observe
These energetic mammals scurrying up and down oak trees and eating and burying acorns
without wondering about their complex relationship with trees. Are squirrels dispersers
(5) and planters of oak forests or pesky seed predators? The answer is not simple. Squirrels
may devour many acorns, but by storing and failing to recover up to 74 percent of them
(as they do when seeds are abundant), these arboreal o\rodents can also aid regeneration
and dispersal of the oaks.
Their destructive powers are well documented. According to one report, squirrels
(10) destroyed tens of thousands of fallen acorns from an oak stand on the University of
Indiana campus. A professor there estimated that each of the large while oaks had.
Produced between two and eight thousand acorns, but within weeks of seed maturity,
Hardly an intact acorn could be found among the fallen leaves.
Deer, turkey, wild pigs, and bears also feed heavily on acorns, but do not store them,
(15) And are therefore of no benefit to the trees. Flying squirrels, chipmunks, and mice are
Also unlikely to promote tree dispersal---whose behavior of caching (hiding) acorns below
The leaf litter often promotes successful germination of acorns---and perhaps blue jays,
Important long-distance dispersers, seem to help oaks spread and reproduce.
Among squirrels, though, there is a particularly puzzling behavior pattern. Squirrels
(20) pry off the caps of acorns, bite through the shells to get at the nutritious inner kernels,
and then discard them half-eaten. The ground under towing oaks is often littered with
thousands of half-eaten acorns, each one only bitten from the top. Why would any animal
waste so much time and energy and risk exposure to such predators as red-tail hawks only
to leave a large part of each acorn uneaten? While research is not conclusive at this point,
(25) one thing that is certain is that squirrels do hide some of the uneaten portions, and these
acorn halves, many of which contain the seeds, may later germinate.
选项
A、The ecology of oak trees
B、Factors that determine the feeding habits of Squirrels
C、Various species of animals that promote the dispersal of tree seeds
D、The relationship between squirrels and oak trees
答案
D
解析
转载请注明原文地址:http://tihaiku.com/zcyy/3335186.html
相关试题推荐
Whatspecialconditionsapplytothefollowingrides?ChooseFOURanswersfromt
Whatspecialconditionsapplytothefollowingrides?ChooseFOURanswersfromt
Choosethecorrectletter,A,BorC.[br]Whodidobtainthespecialexperience
Choosethecorrectletter,A,BorC.[br]Whatisspecialaboutthepool’scons
Choosethecorrectletter,A,BorC.[br]Whodidobtainthespecialexperience
Whatspecialconditionsapplytothefollowingrides?ChooseFOURanswersfromt
Whatspecialconditionsapplytothefollowingrides?ChooseFOURanswersfromt
Whatspecialconditionsapplytothefollowingrides?ChooseFOURanswersfromt
Insulinismanufacturedbyspecializedcellsinthepancreasandreleased______
Onlywith(early)sevencenth-century(observers)didthemusicofthe(original
随机试题
There’ssomethingwrong______mybike.Canyouhelpme?A、toB、forC、withCsomet
Angeroftenmakesusuncomfortable.It’suncomfortabletowitnessanduncomf
[originaltext]W:Hi,Larry,areyouwaitingtoseeProfessorJamison,too?M:Y
TheAmericaneconomicsystemisorganizedaroundabasicallyprivate-enterpr
Theword"tips"inthefirstsentenceofthesecondparagraphmeans______.[br]
党的十九大报告明确了新时代文化建设的基本方略提出了新时代文化建设的基本要求。就是
班氏丝虫病的惟一传染源是A.微丝蚴血症者 B.按蚊 C.致倦库蚊 D.淡色
关于工程咨询服务项目的特点,下列说法正确的有()。A、工程咨询项目具有时效性B
爆破施工时,炮孔布置合理的有( )。A.炮孔方向宜与最小抵抗线方向重合 B.
结核性脑膜炎A.细胞数200×106/L、蛋白正常、糖降低、氯化物正常 B.细
最新回复
(
0
)