奥妙无穷

Explanation: Austria: profound. Known that one is not easy and wonderful interesting very much. 　　Usage: The main predicate; as the predicate attribute, object; describe something or someone unpredictable, unpredictable 　　Source: Yang Chengwu: "layers of fire front burning Maverick": "disguised attack on the use of infinite mystery ... ... and sometimes disguised attack on the Japanese puppet, sometimes disguised attack on the Japanese puppet." Thesaurus:  change constantly, Infinite variety, be most changeful, fantasticality, vagary, vary contingency, there is a sudden change in the situation, make still further progress, change constantly like cloud and wave, lubricity, vagrancy, diversity, ebb and flow contingency, ebb and flow boundless, obliterate, sudden change of a situation, Changing situation, Yunjuefenggui, Ghost out of power into, Ghost out empathic, Ten of nine changes, give oneself a shake and change into another form, Hey presto!, chop and `change keep changing one's plans, opinions, etc