To my surprise, my good friend _________ stay up to study to prepare for the next important exams

organized by ten famous high schools.   [    ]

A. should    

B. may      

C. must  

D. can

(1)解放战争 (2)抗日战争 (3)中 * * 党建立 (4)马克思主义传播 (5)中华人民共和国成立( )

A．4―3―2―1―5

B．4―3―1―2―5

C．3―4―2―5―1

D．3―4―1―2―5