桑枝的功效有（）。
A.祛风湿
B.利水消肿
C.利关节
D.清热解毒
E.凉血消肿
参考答案：A, C
An analyst does research about relationship between duration and actual price. An option-free bond having the duration of 8, if yields decrease by 100 basis point, the actual price of the bond will:（）
A. increase by more than 8%.
B. increase by less than 8%.
C. decrease by more than 8%.
"情势变迁"原则不适用于（）。
A、多边公约
B、边界条约
C、国际信贷合同
D、国际货物买卖合同
