不经计算，通过直接判定得知图示桁架中零杆的数目为：（）
A.1根
B.2根
C.3根
D.4根
参考答案：C
I have had enough cake . Would you like ?
A．any more
B．one more
C．some more
D．another one
重度营养性缺铁性贫血合并肺炎，输浓缩红细胞量应是：（）
A.1~3ml/kg
B.3~5ml/kg
C.5~8ml/kg
D.8~10ml/kg
E.10~15ml/kg
