There were two boys in the lab,       did the experiment successfully.

A．the clever of whom

B．the cleverer or whom

C．the clever of them

D．the more clever of them

脾切除术（）

A.消除脾功能亢进

B.降低门静脉压力

C.防止食管下端静脉破裂出血

D.减轻腹水

E.减少门静脉供血