对钢的性能有益的元素是（）。
A．硅和锰
B．硫和磷
C．硅和硫
D．锰和硫
参考答案：A
钢的分类方法有（）。
A．按化学成分分类
B．按质量分类
C．按用途分类
D．按冶炼方法分类
E．按脱氧程度分类
She _____ an old friend of hers yesterday while she was shopping at the department store.
A．turned down
B．dealt with
C．look after
D．came across
