轮轨润滑装置的故障不包括（）。
A、闸瓦偏磨
B、油罐内无油脂
C、压力空气不足
D、喷嘴堵塞
参考答案：A
正常条件下的终尿约占肾小球滤过液量的()
A．10%
B．20%
C．30%
D．1%
E．5%
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.
