My teacher takes great trouble ______me learn English, since I have a lot of trouble _____it.      [ ]

A. helping; learning  

B. to help; to learn  

C. helping; to learn  

D. to help; learning

正常妊娠满12周时，子宫底于

A．腹部不能触及

B．耻骨联合上不能触及

C．耻骨联合上2～3横指

D．脐耻之间

E．脐下2横指