   where can I found some knowledge
look at pic. in order to find the knowledge of # and ## I look a bunch of books and find nothing. finally it is here. -- mobile and embeded development .OMG.it is online msdn. and I look my msdn on disk(with vs2003)it c++ reference is under another sort  who show me how to find knowledeg fast and effective?   
  Using this Google search, this, MSDN C++ Preprocessor Reference, was the first link.  I find that Google searches large sites (MSDN, Wikipedia, About.com, etcetera) better than the sites themselves usually.   