问题
选择题
______ 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
答案：B
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。
