首页
登录
职称英语
The most popular organic gem is the pearl. A pearl is the response of a mari
The most popular organic gem is the pearl. A pearl is the response of a mari
游客
2025-02-03
34
管理
问题
The most popular organic gem is the pearl. A pearl is the response of a marine mollusk to the presence of an irritating impurity accidentally introduced into its body; a cultured pearl is the result of the intentional insertion of a mother-of-pearl bead into a live mollusk. Whether introduced accidentally or intentionally, the pearl-making process is the same: the mollusk coats the irritant with a substance called nacre. Nacre is composed chiefly of calcium carbonate. Because very few natural pearls are now on the market, most pearls used in fine jewelry are cultured. These include "Biwa" pearls and most other freshwater pearls. Cultured pearls are not easily distinguished from natural pearls except by an expert. [br] The main idea in this passage is that ______
选项
A、most marketable pearls are cultured because nature does not produce enough of its own to satisfy the market
B、cultured pearls are of a higher quality than natural pearls
C、there are two major methods of pearl-making
D、a natural "drought" of pearl production is taking place
答案
C
解析
阅读全文可知本文介绍了珍珠有天然和人工养殖两种形成方式;所以选项C正确。
转载请注明原文地址:https://tihaiku.com/zcyy/3940802.html
相关试题推荐
Themostpopularorganicgemisthepearl.Apearlistheresponseofamari
Themostpopularorganicgemisthepearl.Apearlistheresponseofamari
Themostpopularorganicgemisthepearl.Apearlistheresponseofamari
Electronicmailhasbecomeanextremelyimportantandpopularmeansofcommu
Electronicmailhasbecomeanextremelyimportantandpopularmeansofcommu
Electronicmailhasbecomeanextremelyimportantandpopularmeansofcommu
Electronicmailhasbecomeanextremelyimportantandpopularmeansofcommu
Electronicmailhasbecomeanextremelyimportantandpopularmeansofcommu
Electronicmailhasbecomeanextremelyimportantandpopularmeansofcommu
Electronicmailhasbecomeanextremelyimportantandpopularmeansofcommu
随机试题
Inperiodofthesummerholidaystherewillbearevisedschedule(修改过的时刻表)of
Althoughthefirstyearisreallyimportantforlanguagedevelopmentinchi
Althoughfewwoulddenythatit’sbettertoberichthanpoor,forsomepeop
[originaltext]W:I’mreallylookingforwardtothistripwithourgeologyclass
ThescientificnameistheHoloceneAge,butclimatologistsliketocallour
可燃物质在空气中与()接触,达到某一温度时,开始产生()的燃烧,并在火源
麸炒时,麦麸一般用量为每100kg药物,用麦麸A.30kgB.10~15kgC.
典型的肝性脑病可见生化改变为A.芳香族氨基酸含量降低 B.血氨浓度升高 C.
关于抽样检验的说法,错误的是()。 A.抽样检验适用于大批量的产品检验 B.
抑制土豆发芽采用( )。A.腌渍保藏 B.高温杀菌法 C.巴氏消毒法 D
最新回复
(
0
)