在回收站中，（）恢复对U盘的误删除操作
A.能
B.不能
C.有时能，有时不能
D.不能确定
参考答案：B
An analyst does research about option-free bond price change due to both duration and convexity impacts. The duration of an option-free bond is 9.92, and the convexity measure for that bond is 63.8. If interest rates increase by 200 basis points, the bond's percentage price change is closest to:（）
A. -22.39%
B. -18.56%
C. -17.29%
人的心理是（ ）。
A．脑的机能
B．客观现实的反映
C．大脑活动的产品
D．一种看得见的现象
