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
2025-02-01
42
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 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] 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
细节题型。本题可用排除法。见第二段第一句:Some natural fragrances are easilysynthesized;these include vanillin, the aromatic ingredient in vanilla,andbenzaldehyde,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/3937800.html
相关试题推荐
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
Thefirstrecordeduseofnaturalgastolightstreetlampsitwasinthetowno
______scientistshaveobservedincreasedpollutioninthewatersupply.A、LateB、
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
随机试题
Howoftenonehearschildrenwishingtheyweregrownupandoldpeoplewishi
Managementjargoncanalienatestaffandleavebosseslookinguntrustworthy
Directions:Thispartistotestyourabilitytodopracticalwriting.Youarer
"MadeinChina"lostitsnovelty(新颖)longago.Thelabelhasbecome【C1】______
我国《建设工程质量管理条例》规定,建设工程发包单位不得迫使承包方以()。
心房颤动常见于A.甲状腺功能低下 B.风心病二尖瓣狭窄 C.高血压性心脏病
在目标管理中,对目标的正确描述是A.目标数目越多越好 B.目标应明确、恰当
在贫困救助中,下列属于社会工作者在个人改善层面上的社会工作的是()。A:提高最低
土压平衡盾构施工时,减小盾尾脱出导致地层变形的措施有()。A.改良泥土的塑流
下列关于高压无气喷涂优点的说法,正确的有()。A.改善了劳动条件 B.污
最新回复
(
0
)