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
2023-12-30
55
管理
问题
Natural flavorings and fragrances are often costly and limited in supply. For example, the essential 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 identify 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] During the global COVID-19 pandemic, the team worked hard to help customers
suffered
financial hardship,
enabled
them to keep their cover in place through financial assistance processes.
选项
A、who were suffering; enabling
B、suffering; enabled
C、who had suffered; which enabled
D、who were suffered; and enabled
答案
A
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3318340.html
相关试题推荐
With2005fastbecoming"theyearofthenaturaldisaster",itistimetore
With2005fastbecoming"theyearofthenaturaldisaster",itistimetore
With2005fastbecoming"theyearofthenaturaldisaster",itistimetore
With2005fastbecoming"theyearofthenaturaldisaster",itistimetore
With2005fastbecoming"theyearofthenaturaldisaster",itistimetore
With2005fastbecoming"theyearofthenaturaldisaster",itistimetore
With2005fastbecoming"theyearofthenaturaldisaster",itistimetor
With2005fastbecoming"theyearofthenaturaldisaster",itistimetor
With2005fastbecoming"theyearofthenaturaldisaster",itistimetor
With2005fastbecoming"theyearofthenaturaldisaster",itistimetor
随机试题
Whatisa"stillMe"(Line1,Para.1)accordingtothetext?[br]Howmanyarti
(l)Naturally,inagroupofanimalsasdiverseasthesnakes,andwithsoma
We’vebecomearathergerm-phobic(恐惧症)society,whatwithourantibacterial
Whatcanweinferfromthispassage?[originaltext]ThesuiciderateinAmeric
学校教学工作的基本组织形式是()。A.课堂教学 B.电化教学 C.复式
用一级普通平板玻璃经风冷淬火法加工处理而成的是以下哪种玻璃?( )A.泡沫玻璃
患者,男性,60岁,高血压20余年,突发头痛、视矇、失语,测血压210/130m
左边给定的是多面体的外表面,右边哪一项能由它折叠而成?请把它找出来。 A.如上
下列关于集团审计中重要性的说法中,错误的是( )。 A.集团项目组需要在制定
(2017年真题)下列工程质量事故中,可由事故发生单位组织事故调查组的是( )。
最新回复
(
0
)