[单项选择]公文的主题鲜明是指（）。
A. 公文要正确地反映现实社会的实际情况，符合科学发展观的要求，符合党和国家的方针和政策，并能够以此去解决现实社会中急需解决的矛盾和广大人民迫切要求解决的问题
B. 指一篇公文只能表达一个主要意图、基本观点
C. 指主题要清楚明白，赞成什么，反对什么，提倡什么，抵制什么，应让人一目了然，一读即懂
D. 作者的思想认识即基本观点和看法

Salt, shells or metals are still used as money in out-of-the-way parts of the world today.
Salt may seem rather a strange (1) to use as money, (2) in countries where the food of the people is mainly vegetable, it is often an (3) necessity. Cakes of salt, stamped to show their (4) , were used as money in some countries until recent (5) , and cakes of salt (6) buy goods in Borneo and Darts of Africa.
Sea shells (7) as money at some time (8) another over the greater part of the Old World. These were (9) mainly from the beaches of the Maldives Islands in the Indian Ocean, and were traded to India and China. In Africa, shells were traded fight across the (10) from East to West.
Metal, valued by weight, (11) coins in many parts of the world. Iron, in lumps, bars or rings, is still used in many countries (12) paper money. It can either be exchanged (13) goods, or made int
A. but
B. and
C. so
D. even

Man first appeared on the earth about 2 million years ago. Then he was little more than an animal; but early man had a big advantage over the animals. He had in his brain special groups of nerve cells, not present in animals that enabled him to invent a language and use it to communicate with his fellow men. 46) This ability to speak was of great value because it allowed men to share ideas, and to plan together, so that tasks impossible for a single person could be successfully undertaken by intelligent team-work. Speech also enabled ideas to be passed on from generation to generation so that the stock of human knowledge slowly increased.
It was this special ability that put men far ahead of other living creatures in the struggle for existence. 47) He mastered darkness first with dim lights and later with brighter and brighter lamps, until he can now make for himself so dazzling a light with an are lamp that, like the sun, it is too strong for his naked eyes.