长夜难明

Explanation: Long, dark metaphor rule. 　　Source: Mao Zedong, "Mr. Liu Yazi Huan Xisha and" difficult to understand the word red county day night, monsters dancing in a hundred years, the people are not happy billion. " 　　Examples: ~ Red County days, Fluttering and dancing in a century monster, the people are not happy billion. (Mao Zedong "Huanxi Sha and Mr. Liu Yazi," words)