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
8
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] From the passage we can learn that______.
选项
A、natural flavorings and fragrances are not quite dear
B、the limitation of natural flavorings and fragrances is clear
C、the supply of natural flavorings and fragrances is adequate to meet the demand
D、the cost of producing natural flavorings and fragrances is high
答案
D
解析
细节题型。见第一段第一句:Natural flavorings and fragrances are often costly andlimited in supply.因此选项D为答案。
转载请注明原文地址:https://tihaiku.com/zcyy/3937797.html
相关试题推荐
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
Wheneverwehearofanaturaldisaster,wefeelsympathetictothepeopletobe
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
随机试题
Women’smindsworkdifferentlyfrommen’s.Atleast,thatiswhatmostmena
[originaltext]M:That’sscream’sprenupright.Imean,youshouldjustgetapr
[originaltext]Duringastateofdeeprelaxation,severalphysiologicalchan
[originaltext]Inthepastfewmonths,I’vebeentravelingforweeksatati
面黑黯淡者,多属()A.肾虚水饮 B.肾阳虚 C.肾阴虚 D.瘀
患者男,68岁,8年来站立或腹压增高时反复出现右腹股沟肿物,平卧安静时肿块明显缩
()是用以装载无包装的大宗货物的船舶。A:杂货船 B:散装货船 C:冷藏船
军团菌肺炎的病变特点有 A.可表现为肺大叶的炎症B.可表现为小叶融合性炎症
共用题干 一般资料:求助者,女性,27岁,某公司职员。案例介绍:求助者是家中独
按金融交易涉及的地域不同进行划分,金融市场可分为()。A.债务融资市场 B.
最新回复
(
0
)