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
2024-01-02
65
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] Which of the following is NOT true according to the last paragraph?
选项
A、Synthetic fragrances can be used to make a used car smell like a new one.
B、Synthetic flavors and fragrances have added to the varieties of products.
C、Lemon soap is made out of some delicious lemon.
D、It is likely that a bottle of orange juice is synthesized.
答案
C
解析
可用排除法:选项A、D的内容见第四段后半句,选项B的内容见第四段前半句:只有选项C的内容未被提及(因为lemon柠檬属于natural substance,不是人工合成物),所以是答案。
转载请注明原文地址:https://tihaiku.com/zcyy/3326012.html
相关试题推荐
Sinceprehistoricpeoplefirstappliednaturalpigmentstocavewalls,______ha
[img]2012q1/ct_etoefm_etoeflistz_0438_20121[/img][br]Whatnaturalfeaturesof
"GeothermalEnergy"→Geothermalenergyisnaturalheat
"GeothermalEnergy"→Geothermalenergyisnaturalheat
"GeothermalEnergy"→Geothermalenergyisnaturalheat
"GeothermalEnergy"→Geothermalenergyisnaturalheat
"GeothermalEnergy"→Geothermalenergyisnaturalheat
"GeothermalEnergy"→Geothermalenergyisnaturalheat
AlltheplanetsintheSolarsystemexceptMercuryandVenushavenaturalsatell
EnergyfromNaturalGas1.Muchoftheworldgetsitsene
随机试题
______isthelastandmostcontroversialnovelofD.H.Lawrence.A、SonsandLovers
【S1】[br]【S7】what→which连接词误用。inwhich在本句中引导定语从句,相当于where,介词in后可接which,但不可用what
下列有关辞格的表述,错误的有( )。A.对偶就是把意义相关、字数相等、结构相同
某三跨连续梁桥进行定期检查,经综合技术状况评定后,该桥评定为四类桥。结合上题内容
足月初产妇,昨日上午10时开始规律宫缩,12时破水,至今日下午6时胎儿不下。查:
股票上市交易申请经证券交易所审核同意后,签订上市协议的公司应当在规定的期限内公告
《10kV-500kV输变电设备交接试验规程》中规定,小电阻接地系统接地装置的接
在“基本生产”账户下设置“废品损失”明细账,组织核算生产过程中发生的废品损失,核
编制项目质量管理规划时,主要施工方案的描述中应包括()。A:工程施工次序的总体安
女,35岁。诊断支气管哮喘2年,间断口服糖皮质激素及氨茶碱治疗,时有发作。该患者
最新回复
(
0
)