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
40
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] Cultured pearl is formed by ______.
选项
A、insertion of a pearl into a live mollusk
B、an oyster into which a piece of grit has been placed
C、putting in a live mollusk
D、placing a bead into culture
答案
B
解析
文章第二句(…a cultured pearl is the result of the intentional insertion of a mother- of-pearl bead into a live mollusk.)指出:人工培育的珍珠是在活的贝类中人为加入珍珠母珠(the intentional insertion of a mother-of-pearl bead):所以选项 B.an oyster into which a piece of grit(粗沙)has been placed正确。
转载请注明原文地址:https://tihaiku.com/zcyy/3940803.html
相关试题推荐
Themostpopularorganicgemisthepearl.Apearlistheresponseofamari
Themostpopularorganicgemisthepearl.Apearlistheresponseofamari
Themostpopularorganicgemisthepearl.Apearlistheresponseofamari
Electronicmailhasbecomeanextremelyimportantandpopularmeansofcommu
Electronicmailhasbecomeanextremelyimportantandpopularmeansofcommu
Electronicmailhasbecomeanextremelyimportantandpopularmeansofcommu
Electronicmailhasbecomeanextremelyimportantandpopularmeansofcommu
Electronicmailhasbecomeanextremelyimportantandpopularmeansofcommu
Electronicmailhasbecomeanextremelyimportantandpopularmeansofcommu
Electronicmailhasbecomeanextremelyimportantandpopularmeansofcommu
随机试题
Mostchildrenwithhealthyappetitesarereadytoeatalmostanythingthati
Thenewmedicalinsurancesystemthatwillseegradualintroductionthisyea
Franklyspeaking,I’dratheryou______anythingaboutitforthetimebeing.A、d
HanswasalmostputintodespaironhearingthathiscargotoBrazil___________
心理咨询的主要任务是()A.调适性任务和发展性任务 B.治疗性任务和辅导性任务
Thechangeinthatvillagewasmiraculou
毛泽东指出:“人民这个概念在不同的国家和各个国家的不同历史时期,有着不同的内容。
社会主义宏观经济调控的对象是()。A.国有企业 B.国民经济关键行业
根据《中华人民共和国民事诉讼法》,下列由人民法院作出的裁定中,可以上诉的有()。
2016年12月20日,甲公司以4800万元购入一台设备并立即投入使用,预计使用
最新回复
(
0
)