流体内部各流层之间发生相对滑动时，层面之间存在内摩擦力表述为流体的（）
A.抗剪性
B.抗变性
C.粘性
参考答案：C
An analyst does research about difference between an option-free bond and a callable bond. Compared to an otherwise identical option-free bond, a callable bond is least likely to have:（）
A. a more uncertain cash flow pattem.
B. less price appreciation potential as interest rates fall.
C. more price depreciation potential as interest rates rise.
被西方人称为“科学管理之父”的是（）
A.泰勒
B.霍桑
C.韦伯
D.法约尔
