— Mike, what did our monitor say just now?

— Every boy and every girl as well as the teachers who _____ to visit the museum _____ asked to be at

   the school gate before 6:30 in the morning. [ ]

A. is ; is

B. are; are

C. is; are

D. are; is

已知每根木料的截面尺寸为70mm×200mm，长度为4m，计算使用25根时的木料总体积。