若a与b互为倒数，则a²⁰⁰⁸•（-b）²⁰⁰⁷的值是（　　）

A．a

B．-a

C．b

D．-b．

I'm afraid there are two uncorrected mistakes in your paper. The underlined part means ______. [     ]

A. mistakes which are not correct

B. mistakes which are incorrect

C. mistakes which have been corrected

D. mistakes which haven't been corrected