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
2024-01-01
52
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 and limited in supply.因此选项D为答案。
转载请注明原文地址:https://tihaiku.com/zcyy/3325552.html
相关试题推荐
Damsarecostly,butoncetheyhavebeenbuilt,______electricityverycheaply.A
Thelimitedgaincouldhardlyserveasarelievingjustificationforthetremend
Norwayis,quitenaturally,payinggreatattentiontodevelopmentsinEuropeand
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
随机试题
Shewasdeliriouslastnight,butsheseemsquitelucidthismorning.A、rational
Theprocessofperceivingotherpeopleisrarelytranslated(toourselveso
[originaltext]W:3346791.M.Isthatyou,Sue?W:Who’scalling?M:ThisisMik
[originaltext]W:Rockstarsnowfaceanewhazard—voiceabuse.Afterlastweek’
以下属于抗凝剂的有()。A:肝素 B:EDTA C:枸橼酸盐 D:干扰素
按照《证券监督管理条例》的要求,以下关于证券公司持续监管方面的规定,错误的是(
A.樟脑B.梓醇C.青蒿素D.莪术醇E.穿心莲内酯具有抗疟活性的是
变压器一次绕组加额定电压,二次绕组带负载运行时,二次电压大小将随()的改
《城市给水工程规划规范》中,符合“给水系统安全性”说法的是( )。A.工程设施
(2018年真题)甲公司生产甲、乙两种联产品,2018年9月,甲、乙产品在分离前
最新回复
(
0
)