问题
选择题
在美洲生活在北冰洋沿岸的居民是( )
A.印第安人
B.欧洲移民
C.因纽特人
D.黑种人
答案
答案:C
题目分析:
在美洲,是因纽特人生活在北冰洋沿岸的地区,属于黄色人种,他们的传统民居是冰屋,故本题选C。
在美洲生活在北冰洋沿岸的居民是( )
A.印第安人
B.欧洲移民
C.因纽特人
D.黑种人
答案:C
题目分析:
在美洲,是因纽特人生活在北冰洋沿岸的地区,属于黄色人种,他们的传统民居是冰屋,故本题选C。
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 free 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. |
The difference between a pearl and a cultured pearl is the nature of the ______.
A.color
B.introduction of the irritating impurity
C.coating material
D.irritating impurity