急性多房性脓胸最适宜的治疗方法是（）

A.大剂量抗生素治疗

B.胸腔穿刺排脓

C.胸腔闭式引流

D.开胸清除脓液，闭式引流

E.胸廓改形术

I am wondering ______________.

A．why did he come to school late

B．why he came to school late

C．that he came to school late

D．why was he late for school