泛泛而谈

Explanation: General: usually, no depth. Generally too abstract to talk about. 　　Source: Mao Dun, "How to evaluate <Song of Youth>" also because of the time, not the "Song of Youth" and then reread it again write, therefore I can only generalities can not be cited for specific analysis of the original. " 　　Examples: Also because of the time, not the "Song of Youth" and then reread it again write, therefore I can ~, can not quote the original for specific analysis. (Mao Dun, "How to evaluate <Song of Youth>"