普碳钢中，Mn/Si控制在（）左右，可得到完全液态的脱氧产物，以改善钢水流动性。
A．2.5
B．3.0
C．3.5
参考答案：B
----Do you think Tim did well in the English speech contest?
----______. He won the first place.
A．He couldn’t have done better.
B．He played naturally
C．He was not nervous at all
D．I couldn’t agree more
下列关于金霉素倍他米松糊剂的说法正确的是（）
A.药理作用为抗菌，降低毛细血管通透性
B.处方组成为盐酸金霉素粉0.25g，倍他米松1.5mg，甘油5ml
C.可用于真菌性口炎
D.可用于复发性口疮的治疗
E.可口服用药
