who knows?"The application of double isotope effects in enzyme kinetics".我只知道是个化学领域的词汇,但具体含义呢

Who Knows Where The Time Goes 歌词 who knows what is the life? who knows the meaning of my name? who knows who knows? Who knoWS? I know the man who knows who knows who.这好像是个谚语 who knows what will happen in the future How many nations are there in the world?who knows? Who knows how many countries there are on the earth Who knows the answer?Me和 I 应选哪个 In the late night,insomnia,and who knows? God knows who is the only one I love Cried the fish.Water know.I cried.Who knows? WHO KNOWS WHAT IS THE MEAN OF COLLAPSARWAN? Help!Who knows the meaning of macrocontextual and microcontextual? Who knows the answers 2 my science study guide! Nobody really knows who the woman was.这个是什么用法?