—All the students in Class One went to the cinema           Li Ping. Why?

—Because he had a stomachache.       [ ]

A. besides                    

B. without

C. except                    

D. beside

经腹扫查，妊娠几周时可显示妊娠囊结构（）

A.4周

B.4～5周

C.5周

D.5～6周

E.7周