裸导线主要有哪些？
参考答案：
铜导线、铝导线、钢芯铝导线。
钢筋混凝土板受力钢筋的间距不应小于（）
A、50mm
B、60mm
C、70mm
D、100mm
If interest rates fall, the:（）
A. callable bond’s price rises faster than that of a noncallable but otherwise identical bond.
B. callable bond’s price rises more slowly than that of a noncallable but otherwise identical bond.
C. value of call option embedded in the callable bond fails.
