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
2025-02-02
28
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/3940112.html
相关试题推荐
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
Thefirstrecordeduseofnaturalgastolightstreetlampsitwasinthetowno
OneofthemostbeautifulnaturalwondersintheUnitedStatesmustcertainlybe
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
Naturalflavoringsandfragrancesareoftencostlyandlimitedinsupply.Fo
With2005fastbecoming"theyearofthenaturaldisaster",itistimetore
随机试题
Whenimaginativescientistsfirstsuggestedthepossibilitythatoneperson
茶对中国文化有着深远的影响。在中国社会,年轻一辈常常向老一辈敬茶以表示对他们的尊敬。中国人在家庭聚会时也会喝茶。子女们很少有时间回来探望父母,父母也很少
CoastAlonginUnspoiltTurkey(Ⅱ)畅游在原始的土耳其(Ⅱ)Packsuchactivitie
Volumeshavebeenwrittenabouttechnology’sabilitytoconnectpeople.
麻黄科植物草麻黄的干燥草质茎人药,称为A.草麻黄 B.木贼 C.麻黄 D.
C
下列有关资产负债表日后事项的处理,表述错误的是()。A.日后期间发现报告年度资
患者,女,27岁。发热,腹痛拒按,腹泻,大便赤白相间,里急后重,舌红苔黄腻,脉滑
骨巨细胞瘤的常见X线表现是( )。A.“肥皂泡”样改变 B.“日光射线”形态
我国金融机构发放的中期贷款最长期限为()年。A.8 B.6 C.5 D.3
最新回复
(
0
)