谜中谜

然而REM睡眠，却是众所皆知的包于谜团中的谜中之谜。

REM sleep , however , is the proverbial riddle wrapped in a mystery inside an enigma .

而希斯克里夫和凯瑟琳的爱情故事，是艾米莉·勃朗特杰作《呼啸山庄》的核心与精髓，也是难解的谜中之谜。

The story is also called " the riddle of riddles " .

有了全球企业界的鼓励、理解和公平竞争，我相信，俄罗斯谜中之谜的形象将会一去不复返。

With the encouragement , understanding and healthy competition of the international business community , I am confident that the enigma image can be put aside for good .