钢号T12A中的“T”表示（）。
A.普通碳素结构钢
B.优质碳素结构钢
C.碳素工具钢
D.弹簧钢
参考答案：C
A building was ____ in a fire in Hengyang, making 20 firefighters killed and about 16 people ____.[ ]
A. tore down; wounded
B. burned down; injured
C. put down; harmed
D. knocked down; hurt
体内氧分压最高的部位是
A．淋巴液
B．静脉血
C．肺泡气
D．组织液
E．动脉血
