with her work she didn't even notice the heavy snowfall outside the window.A. Occupying　

问题补充：

with her work, she didn even notice the heavy snowfall outside the window.

A. Occupying

B. To be occupied

C. Having occupied

D. Occupied

答案：

A. Occupying

B. To be occupied

C. Having occupied

(答案→)D. Occupied

解析：考查非谓语动词。分析句子结构可知，此处用过去分词作原因状语。be occupied with sth 表示“忙于某事”。