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
1 While everybody enjoys fresh cut flowers around their house, few people know how to keep them for as long as possible. This m
1 While everybody enjoys fresh cut flowers around their house, few people know how to keep them for as long as possible. This m
admin
2011-01-22
72
问题
1 While everybody enjoys fresh cut flowers around their house, few people know how to keep them for as long as possible. This may be done by keeping in mind a few simple facts.
2 An important thing to remember about cut flowers is that they are sensitive to temperature. For example, studies have shown that cut carnations(康乃馨) retain their freshness eight times longer when kept at 12℃ than when kept at 26℃. Keeping freshly harvested flowers at the right temperatures is probably the most important aspect of flower care.
3 Flowers are not intended by nature to live very long. Their biological purpose is simply to attract birds or insects, such as bees, for pollination(授粉). After that, they quickly dry up and die. The process by which flowers consume oxygen and produce carbon dioxide(二氧化碳), called respiration(呼吸), generates the energy the flower needs to give the flower its shape and color. The making of seeds also depends on this energy. While all living things respire, flowers have a high level of respiration. A result of all this respiration is heat, and for flowers the level of heat relative to the mass of the flower is very high. Respiration also brings about the eventual death of the flower. Thus the greater the level of respiration, the sooner the flower dies.
4 How, then, to control the rate at which flowers die? By controlling respiration. How is respiration controlled? By controlling temperature. We know that respiration produces heat, but the reverse is also true. Thus by maintaining low temperatures, respiration is reduced and the cut flower will age more slowly.
5 Another vital factor in keeping cut flowers is the quality of the water in which they are placed. Flowers find it difficult to "drink" water that is dirty or otherwise polluted. Even when water looks and smells clean, it almost certainly contains harmful substances that can endanger the flowers. To rid the water of these unwanted substances, household chlorine bleach (含氯漂白剂)can be used in small quantities. It is recommended that 15 drops of chlorine bleach( at 4% solution)be added to each liter of water. The water and solution should also be replaced each day.
A.Control of Respiration
B.Beauty of Fresh Cut Flowers
C.Role of Respiration
D.Most Important Aspect of Flower Care
E. Need for Clean Water
F. Ways of Stopping Respiration
Paragraph 2 ______.
选项
答案
D
解析
第二段中最后一句“Keeping freshly harvested flowers at the right temperatures is probably the most important aspect of flower care”为段落中心句,所以不难选出答案为D。
转载请注明原文地址:https://www.kaotiyun.com/show/9jUd777K
本试题收录于:
职称英语综合类A级题库职称英语分类
0
职称英语综合类A级
职称英语
相关试题推荐
TheGreatNewspaperWarUpuntilabout100yearsago,newspapersintheUnitedStatesappealedonlytothemostseriousread
ForecastingMethodsThereareseveraldifferentmethodsthatcanbeusedtocreateaforecast.Themethodforecasterchooses
PlantsinDesertOnlyspecialplantscansurvivetheterribleclimateofadesert,fortheseareregionswheretheannualra
CellPhoneLetsYourSecretsOutYourcellphoneholdssecretsaboutyou.Besidesthenamesandnumbersthatyou’veprogram
Argumentamongthespeakersattheconferenceisborderingonviolence.
WeallknowthatSharonisawomanofstrongpoliticalconvictions.
AIftheGardeners’argumentwassoundBbecauseshewasclevererthanotherchimpsCwhenshewantedtoeatDwhileshewasat
APioneerinModernDanceManyartistslateinthelastcenturywereinsearchofameanstoexpresstheirindividuality.Modern
NormanBlarneyisanartistofdeepconvictions.
Canyouspottheflawintheirargument?
随机试题
粮豆的主要卫生问题是什么?
禁用于慢性阻塞性支气管病患者的抗心律失常药物是
在( )情形下,通过分析公开信息是不可能取得超额收益的。
某区环保局因某新建水电站未报批环境影响评价文件,且已投入生产使用,给予其罚款10万元的处罚。水电站不服,申请复议,复议机关作出维持处罚的复议决定书。下列说法中正确的是()。
与传统定期预算方法相比,下列属于滚动预算方法特点的有()。
下列通过“制造费用”项目核算的有()。
下列各项中,会引起负债和所有者权益同时发生变动的有()。
霉变谷物内主要致肝癌物质是()。
2012年11月11日,某网购电商平台一天的交易额就达到191亿元,超过30家大型商场半年交易额。网购电商平台相对于实体店在前期投入上具有相当的优势。对于这种节约的前期投入,以下概念表述最为准确的是()。
已知函数f(x)具有任意阶导数,且fˊ(x)=[f(x)]2,则当n为大于2的正整数时,f(x)的n阶导数,则f(n)(x)为().
最新回复
(
0
)