when to leave I could only stay at home nothing. A. Knowing not; doneB. Not knowing; d

问题补充：

when to leave, I could only stay at home, nothing.

A. Knowing not; done

B. Not knowing; doing

C. Having not known; done

D. Not having known; doing

答案：

A. Knowing not; done

(答案→)B. Not knowing; doing

C. Having not known; done

D. Not having known; doing

解析：考查非谓语动词，第一空，分词的否定式，not应放在分词的前面，可排除A和C，没有明显的先后顺序，不用分词的完成式，第二空，doing作伴随状语。所以选B。