问题补充：
---Be careful! Your clothes will catch fire.
---Thank you. so close to the fire.
A. I didn’t know I was
B. I don’t know I am
C. I hadn’t known I was
D. I don’t know I was
答案：
(答案→)A. I didn’t know I was
B. I don’t know I am
C. I hadn’t known I was
D. I don’t know I was
解析：考查时态。句意：当心，你的衣服要着火了。——谢谢你。我不知道我的衣服离火是如此的近。结合语境可知主句表示的是刚才的动作，从句描述的刚才的状态，故都用过去时态，选A。
