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
105
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
AweekafterourdaughterLaurenwasborn,mywifeBonnieandIwerecomplete
[img]2018m11s/ct_eyyjsaz2017c_eyyjsacloze_0016_201809[/img]Ahundredyears
[originaltext]W:Haveyoueverattendedagroupinterview?Imeananinterview
《中国基本医疗卫生与健康促进法》于2020年6月1日起实施,这是我国卫生健康领域
平洞根据断面尺寸来划分,断面面积为60平方米时,对应的断面类型是()。A.
证券服务机构为证券的( )等证券业务活动制作、出具审计报告、资产评估报告、财务
上证100指数是从()指数中选取营业收入增长率和净资产收益率综合排名靠前的10
女性,50岁,患慢性迁延性肝炎20余年,近1个月来感全身明显乏力、纳差、腹胀、腹
患者,男性,长期卧床自理困难,最近护理时发现骶尾皮肤发红,除去压力无法恢复原来肤
在完全竞争市场中,企业在短期内是否继续生产取决于价格与()之间的关系。A:边
最新回复
(
0
)