设二叉排序树中关键字互不相同，其中最小元必无左孩子，最大元必无右孩子。此命题是(51)，最小元和最大元一定是(52)。

(30)

(31)

(28)

(29)

(25)

(26)

XML　is　a(71)language　for　documents　containing(72)information.

Structured　information　contains　both　content(words,　pictures,　etc.)and　some　indication　of　what　role　that　content　plays(for　example,　content　in　a　section　heading　has　a　different　meaning　from　content　in　a　footnote,　which　means　something　different　than　content　in　a　figure　caption　or　content　in　a　database　table,　etc.).　Almost　all　documents　have　some　structure.

(24)

(23)

Data　mining　is　an(66)research　field　in　database　and　artificial　intelligence.　In　this　paper,　the　data　mining　techniques　are　introduced　broadly　including　its　producing　background,　its　application　and　its　classification.　The　principal　techniques　used　in　the　data　mining　are　surveyed　also,　which　include　rule　induction,　decision(67),　artificial(68)network,　genetic　algorithm,　fuzzy　technique,　rough　set　and　visualization　technique.　Association　rule　mining,　classification　rule　mining,　outlier　mining　and　clustering　method　are　discussed　in　detail.　The　research　achievements　in　association　rule,　the　shortcomings　of　association　rule　measure　standards　and　its(69),　the　evaluation　methods　of　classification　rules　are　presented.　Existing　outlier　mining　approaches　are　introduced　which　include　outlier　mining　approach　based　on　statistics,　distance-based　outlier　mining　approach,　data　detection　method　for　deviation,　rule-based　outlier　mining　approach　and　multi-strategy　method.　Finally,　the　applications　of　data　mining　to　science　research,　financial　investment,　market,　insurance,　manufacturing　industry　and　communication　network　management　are　introduced.　The　application(70)of　data　mining　are　described.