若要使显微镜视野中的物像从右上方移至视野中央，则应如何移动载玻片（ ） A．向右

治疗温病气分实热证，症见壮热、烦渴、脉洪大，应选用的药物是（）。
治疗温病热盛伤津，口干舌燥，烦渴，应选用的药物是（）。

A.石膏

B.栀子

C.天花粉

D.夏枯草

E.淡竹叶

形状公差中，平面度公差带是指距离为公差值的两平行平面之间的区域。

市场经济的一般规律是市场决定资源配置

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.

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