神鬼莫测

Explanation: Measurement: speculation. It seems highly secretive, Bourne is also unpredictable degrees. Guess no one can describe. 　　Source: Ming Luo, "Three Kingdoms" eighty-seventh back Zhujiang are Baifu said 'the prime minister Machine Operators, Bourne unpredictable. '" 　　Examples: Thought of this, he looked up from his Weihu only fifty Yubu hall, and thirty seconds later, this good and bad are difficult, unpredictable Bourne struggles to begin. (Qu Bo "Linhaixueyuan" 20