Though they are______little children , they have worked out _______many difficult math problems.

A．so; so

B．such; such

C．so; such

D．such; so

渗出性胸腔积液的特点是（）

A.比重>1.018

B.白细胞>0.5×10/L

C.葡萄糖<1.11mmol/L

D.Rivalta试验阳性

E.胸液/血清LDH>0.6