如果管道周围有硫代硫酸盐存在时，（）与硫代硫酸盐反应生成硫酸，从而腐蚀管道。

A.硫酸盐还原菌

B.好氧菌

C.硝酸盐还原菌

D.厌氧菌

A 5 percent coupon bond with semi-annual coupon payments on a coupon payment date when the coupon has NOT been paid yet and the bond has a $1000 par value. What is the accrued interest of the bond and what is the bond’ s full price. Accrued Interest Full Price ①A. $ 25 $1000 ②B. $25 $1025 ③C. $50 $1050（）

A．①

B．②

C．③