[单项选择]According to the first paragraph, the atmosphere is essential to man in that ______. A) it protects him against the harmful rays from space B ) it provides sufficient light for plant growth C) it supplies the heat necessary for human survival D) it screens off the falling meteors

Paragraph One: According to the record in the inscriptions(题字，碑铭), ancient China Post originated in the Yin-Shang Dynasty, prosperous (繁荣)in the Zhou Dynasty, popular in the Spring-Autumn and the Warring States Periods (770-221 B. C). Confucius said, "The propagation (传播) of moral is as rapid as post delivery", which described the popularity of the post.Paragraph Two: Ancient Chinese post system was the special communication organization for govern ment, which only delivered official documents and not private letters. Public communication which was organized by individuals developed slowly. By the coddle stage of Ming Dynasty, with the progress of productive forces and the increase of the requirements for public communication, private-owned post offices were created. By late Qing, the number of private owned post offices had exceeded several thousands, forming their own communication network, which became the public communication org