她掌握德语和俄语的实用知识。

She has ___a ___working ___knowledge ___of German and Russian.

我掌握英语和西班牙语的实用知识。

I have ___a ___working ___knowledge ___of English and Spanish.

这份工作需要你掌握统计学的实用知识。

You need ___a ___working ___knowledge ___of statistics for this job.