补阳还五汤的功用为()
A.活血祛瘀通络
B.活血行气通络
C.补气行气活血
D.行气祛瘀通络
E.补气活血通络
参考答案：E
Which of the following statements regarding provisions for paying off bonds is least likely correct（）
A. Nonrefundable bonds can be callable.
B. Serial bonds are an issue with several staggered maturity dates.
C. A sinking fund provision gives the company the option to retire portions of the bond issue prior to maturity.
自然人的软件著作权保护期为______。
A．自然人终身 B．50年C．死亡后50年 D．自然人终身及其死亡后50年
