客车基础制动装置中衬套裂纹时，（）。
A.须焊修
B.须不超过2mm可继续使用
C.须整件报废
D.须重新镶套
参考答案：D
在家庭电路中电灯突然熄灭，而用测电笔分别测两根电源线发现氖管仍发亮，发生这种故障的原因是什么？
Exactly one year ago, an investor purchased a $1000 face value, zero- coupon bond with 11 years remaining to maturity. The YTM was 8.0%. Now, one year later, with market rates unchanged, an investor purchases an annuity that pays $ 40 every six months for 10 years. The combined value of the two investments based on the 8% BEY is approximately:（）
A. $966.
B. $1000.
C. $1007.
