首页
登录
职称英语
Natural flavorings and fragrances are often costly and limited in supply. Fo
Natural flavorings and fragrances are often costly and limited in supply. Fo
游客
2025-02-03
24
管理
问题
Natural flavorings and fragrances are often costly and limited in supply. For example, the vital ingredient in a rose fragrance is extracted from natural rose oil at a cost of thousands of dollars a pound; an identical synthetic substance can be made for 1% of this cost. Since the early twentieth century, success in reproducing these substances has created a new industry that today produces hundreds of artificial flavors and fragrances.
Some natural fragrances are easily synthesized; these include vanillin, the aromatic ingredient in vanilla, and benzaldehyde, the aromatic ingredient in wild cherries. Other fragrances, however, have dozens, even hundreds of components. Only recently has it been possible to separate and identit3, these ingredients by the use of gas chromatography and spectroscopy. Once the chemical identity is known, it is often possible to synthesize them. Nevertheless, some complex substances, such as the aroma of fresh coffee, have still not been duplicated satisfactorily.
Many of the chemical compounds making up these synthetics are identical to those found in nature, and are as harmless or harmful as the natural substances. New products must be tested for safety, and when used in food, must be approved by the U.S. Food and Drug Administration.
The availability of synthetic flavors and fragrances has made possible a large variety of products, from inexpensive beverages to perfumed soap to used cars with applied "new car odor." [br] According to the passage, all the following are easier to synthesize EXCEPT ______
选项
A、aromatic ingredient in vanilla
B、vanilla
C、aromatic ingredient in wild cherry
D、the flavor of fresh coffee
答案
D
解析
本题可用排除法。见第二段第一句:Some natural fragrances are easily synthesized; these include vanillin,the aromatic ingredient in vanilla,and benzaldehyde,the aromatic ingredient in wild cherries.选项A、B、C的内容均被提及,因此除外的选项只有D,所以D为答案。(本题答案也可用下一题的推断法推出)
转载请注明原文地址:https://tihaiku.com/zcyy/3940566.html
相关试题推荐
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
Thefirstrecordeduseofnaturalgastolightstreetlampsitwasinthetowno
OneofthemostbeautifulnaturalwondersintheUnitedStatesmustcertainlybe
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
With2005fastbecoming"theyearofthenaturaldisaster",itistimetore
With2005fastbecoming"theyearofthenaturaldisaster",itistimetore
随机试题
[originaltext]TodayI’dliketotalkaboutthesculptorHenryMoore,inpar
[originaltext]W:I’mallpacked.(22)Take-offtimeis2:30a.m.thedayaftert
甲公司只生产一种产品,变动成本率为40%,保本作业率为70%。甲公司的销售利润率
某时期内,某国粮食价格持续下跌。为了保护农民的利益,该国政府因此规定了粮食最低收
下列有关全业使命和愿景的表述,不正确的量()A.企业愿景是比较长期和抽象的 B
#_2是理解科学知识的起点,是学生由不知到知的开端,是知识获得的首要环节。
(2020年真题)根据消费税法律制度的规定,下列应税消费品中,实行从量计征办法计
在确定控制措施或考虑改变现行控制措施时考虑按()顺序选择风险控制方法。A.替代
公路路面工程专业承包企业资质可一共分为()。A.二级 B.三级 C.四级
根据《建设工程安全生产管理条例》,施工单位应当组织专家对施工方案进行论证、审查的
最新回复
(
0
)