问题 解答题

在一个草原生态系统中,狼、草类和兔子的数量关系如图所示,请据图回答下列问题:

(1)A代表的生物是______;B代表的生物是______;C代表的生物是______.

(2)冬天草类减少,兔子数量______,狼的数量______;春天雨量充沛,草类增多,此时兔子数量______,狼的数量______,在一般情况下,三种生物的数量总是维持在相对稳定的状态,这种现象叫______.

(3)由于大量捕杀狼,导致狼在草原中灭绝,草原中的兔将会______.

A.增多     B.减少     C.维持不变     D.先增多后减少

(4)该草原生态系统中所存在的食物链是:______.

(5)A、B、C在该生态系统营养结构中的地位分别是______、______、______.

(6)由于狼被大量捕杀,该生态系统受到破坏,从而使其______能力受到影响.

答案

(1)生产者是一切消费者和分解者物质和能量的源泉,是生态系统的主要成分.生产者和消费者之间吃与被吃的关系形成了食物链,即草→兔→狼.生态系统中的物质和能量就是沿着食物链和食物网流动的,越靠近前端的生物数量越多,越靠近食物链的末端的生物数量越少.A、B、C代表的生物依次是狼、兔、草.

(2)在食物链,草→兔→狼中,兔的数量会因草的减少而减少,狼的数量会因兔的减少而减少,冬天,草类减少,兔子、狼的数量依次减少.草类增多时,兔和狼的数量都会增加.在一般情况下,三种生物的数量总是维持相对稳定的状态,这种现象叫生态平衡.

(3)若大量捕杀狼,则兔的数量先因狼的减少而增加,此时,草的数量因兔的增加而减少,后来则因草的减少而减少.由于大量捕杀狼群,导致狼在草原中灭绝,此时草原中的兔子将会先增多后减少.

(4)在生态系统中,生产者与消费者之间的关系,主要是吃与被吃的关系,这样就形成了食物链;因此食物链是:草→兔子→狼

(5)A、B、C在该生态系统营养结构中的地位分别是最高级消费者,初级消费者,生产者.

(6)在一般情况下,生态系统中各种生物的数量和所占的比例总是维持在相对稳定的状态.这说明生态系统具有一定的自动调节能力,但这种自动调节能力有一定限度,当人为的或自然因素的干扰超过了这种限度时,生态系统就会遭到破坏.

故答案为:(1)狼;兔;草;(2)减少;减少;增加;增加;生态平衡;(3)D;(4)草→兔子→狼;(5)最高级消费者;初级消费者;生产者;(6)自动调节能力.

完形填空
One of my fondest Christmas memories was also one of our family’s bleakest(最令人沮丧的).We were just little kids, and on Christmas Day mom  us all around her to tell us,     , that there would be no presents because all we really wanted was to    for our daddy. He was very sick. I don’t remember anything else except four little girls surrounding my mother, crying       a miracle(奇迹)
At that very moment, someone     loudly on the door.      Behind him was a merry group of soldiers from the Army base where my father    as a minister. News had    that we were in trouble, and his colleagues knew we needed some     .
With all the excitement ,even my dad     in a blanket to keep warm , came down and sat in front of a roaring fire in our room to watch his children be     by good Samaritans(乐善好施的人). The presents were unwrapped, and we girls      packages and found a doll each and four board games.
What is       to me is that I don’t even remember what sickness my father was suffering from.I     remember an evening of laughter and     There were no expensive toys but priceless moments of friendship and fun given by young men who knew that a family was having a(n) rough time . They gave their time and their attention to little children who needed to laugh.
The most important thing in life aren’t things. And what about the true spirit of holidays? I hope we all are able to remember a thing about the holidays that stirs(搅动)our heart , that isn’t really a thing at all, but the smile on a child’s face because we take a moment to hug or wipe away a tear.
小题1:
A.requestedB. gatheredC.commandedD. recommended
小题2:
A.in tearsB. in doubtC. in silenceD. in surprise
小题3:
A.applyB. prayC. payD. ask
小题4:
A.toB. withC. forD. in
小题5:
A.knockedB. beatC. tappedD. struck
小题6:
A.FightingB. ShootingC. FollowingD.Running
小题7:
A.chargedB. existedC. workedD.governed
小题8:
A.expandedB. spreadC. distributedD. disappeared
小题9:
A.confidenceB. cheerC. trustD. wisdom
小题10:
A.dressedB. attachedC. trappedD. wrapped
小题11:
A.persuadedB. savedC. taughtD. entertained
小题12:
A.discoveredB. soughtC. unfoldedD. packed
小题13:
A.strangeB. frighteningC. usefulD. encouraging
小题14:
A.seldomB. justC. evenD. hardly
小题15:
A.anxietyB. surpriseC. doubtD. happiness
单项选择题