可望而不可即
      Explanation: To saw, but not reach or can not close. Metaphor is still often can not be achieved things.
      Source: Song of the question, "Minghe chapter" Minghe expected not amiable, willing to take the raft was one cares. "Ming Liu Ji," Gordon wrote pregnant twenty-eight Wolong Mountain Dance "white clouds in the sky, elusive."
      Examples: In the heights of science to catch up with developed countries is not ~ thing.