200-250km/h的有砟轨道线路轨距静态临时补修标准为（）mm。
A.4，-2
B.6，-4
C.6，-5
D.8，-6
参考答案：B
（）年开始了“尤伯杯”杯。
A.1954
B.1955
C.1956
D.1958
Which of the following statements concerning the arbitrage-free valuation of non-Treasury securities is TRUE The credit spread is:（）
A. only a function of the bond’s default risk.
B. only a function of the bond’s term to maturity.
C. a function of default risk and the term to maturity.
