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
In the past oysters were raised in much the same way as dirt farmers raised tomatoes-by transplanting them.First,farmers selecte
In the past oysters were raised in much the same way as dirt farmers raised tomatoes-by transplanting them.First,farmers selecte
admin
2013-01-20
101
问题
In the past oysters were raised in much the same way as dirt farmers raised tomatoes-by transplanting them.First,farmers selected the oyster bed,cleared the bottom of old shells and other debris,and then scattered clean shells about.Next they “planted”fertilized oyster eggs,which within two or three weeks hatched into larvae.The larvae drifted until they attached themselves to the clean shells on the bottom.There they remained and in time grew into baby oysters called seed or spat.The spat grew larger by drawing in seawater from which they derived microscopic particles of food.Before long,farmers gathered the baby oysters,transplanted them in other waters to speed up their growth,and then transplanted them once more into another body of water to fatten them up。
Until recently the supply of wild oysters and those crudely farmed were more than enough to satisfy people’s needs.But today the delectable seafood is no longer available in abundance.The problem has become so serious that some oyster beds have vanished entirely。
Fortunately,as far back as the early 1900’s marine biologists realized that if new measures were not taken,oysters would become extinct or at least luxury food.So they set up well equipped hatcheries and went to work.But they did not have the proper equipment or the skill to handle the eggs.They did not know when,what,and how to feed the larvae.And they knew 1ittle about the predators that attacked and ate baby oysters by the millions.They failed,but they doggedly kept at it.Finally,in the 1940’s a significant breakthrough was made.
The marine biologists discovered that by raising the temperature of the water,they could induce oysters to spawn not only in the summer but also in the fall,winter,and spring。Later they developed a technique for feeding the larvae and rearing them to spat.Going still further,they succeeded in breeding new strains that were resistant to diseases,grew faster and larger,and flourished in water of different salinities and temperatures.In addition,the cultivated oysters tasted better!
According to the passage,which of the following words best describes the efforts of the marine biologists working with oysters?
选项
A、Persistent.
B、Intermittent.
C、Traditional.
D、Fruitless.
答案
A
解析
细节题。选项A意思是“坚持不懈,持之以恒”,选项B意思是“间歇的,断断续续的”,选项C意思是“传 统”,选项D意思是“无结果的,不成功的”。在文中第三段,倒数第二句They failed,but they doggedly kept at it. (他们失败了,但是他们依然顽强地坚持。)句中用以形容海产学家努力的词是“doggedly”,意为“坚持不懈地”,与选项A中的Persistent意思相近。因此选择A。
转载请注明原文地址:https://kaotiyun.com/show/Rzu7777K
0
大学英语四级
相关试题推荐
Knowledgemaybeacquiredthroughconversation,watchingtelevisionortraveling,butthedeepestandmost【B1】______wayisthrou
America’sTop5CleanestCitiesWhatisacleancity?Ideally,it’saplacewheretheairqualityisgood,thewaterissafe
America’sTop5CleanestCitiesWhatisacleancity?Ideally,it’saplacewheretheairqualityisgood,thewaterissafe
A、3-6monthsofmonthlysalaryB、13%oftheirmonthlysalaryC、10dollarsaweekD、36%oftheirmonthlysalaryA细节题.对话中女士提到,一个人应
InbothChinaandDenmarkchildrenare【S1】______andtheyreceiveagreatdealofattention.However,thewaychildrenareraised
A、Leavemobilephonestotheirfamily.B、Putmobilephonesoutsidethebedroom.C、Sende-mailtotheirfriendsandfamily.D、Sen
A、Becausehehaslivedaremarkablelife.B、BecauseheisthelastAmericanWorldWarIveteran.C、Becausehehaslivedaveryl
______(原本定于上周四举行的运动会)wasfinallycanceledbecauseofthebadweather.
A、HewantedtobeatWard.B、HewantedtohelphisbrotherWard.C、Heenjoyedcompetitioninthisbusiness.D、Hethoughtthisbus
ManandNatureThebalanceofnatureisadelicatesystemofchecksandcounter-checks.Naturehasitsownwayofchecking
随机试题
这本书是为非英语专业学生提高阅读水平设计的。
已知某酶分子由多种亚基组成,测定其酶反应动力学不符合米-曼方程,而是呈“S”形曲线。此酶应属于一种
关于多动综合征预后的说法中正确的是
新《动物防疫法》共有_________章()。
简述田径运动的基础功能。
《晋书.刑法志》:“峻礼教之防,准五服以制罪。"“服制若近,以尊犯卑,处刑则轻,以卑犯尊,处刑则重;服制若远,以尊犯卑,处刑则重,以卑犯尊,处刑则轻。若财产转让有犯,服制若近,处罚若轻。”问题:这段文字反映了什么制度?
内罗毕宣言
五四运动的直接导火线是()
ForestChaletsAgetawaythatyoumusthave...Doestheringingofyouralarmclock,therushforaquickbreakfast,dashingthr
ThepurposeofMagellan’sexpeditionwas______.
最新回复
(
0
)