14. The natural language dialogue method as recited in claim 10 , wherein the step of selecting the at least one report answer comprises: in a speech synthesis database, searching a first speech corresponding to the first keyword included in the first speech input; and selecting one of the at least one report answer conforming to the first speech.
10. The natural language dialogue method as recited in claim 9 , further comprising: arranging the at least one report answer in the candidate list according to the priority.