—Can he work out the maths problem?

—I think ______ hard for him to work it out.[ ]

A. it's  

B. that's  

C. this is    

D. they're

职业纪律包括（）。

A．劳动纪律、组织纪律

B．群众纪律、保密纪律

C．财经纪律、宣传纪律

D．外事纪律