在冶炼中钙的真正重要性有（）。
A.脱氧能力
B.脱硫能力
C.脱氮能力
D.改变硫化物和氧化物形态
E.提高可浇性
参考答案：A, B, D, E
They were_______ busy_______ with each other__________ the time. [ ]
A. too; to talk; to forget
B. too; talking; to forget
C. so; to talk; that they forgot
D. so; talking; that they forgot
交通量的概念是什么？
