--Be careful! You might fall into the water.
--Thank you. I .I so close to the pool.
A. didn't know; am standing
B. don't know; am standing
C. didn’t know; was standing
D. didn't know;Would stand
网友回答
A. didn't know; am standing
B. don't know; am standing
(答案→)C. didn’t know; was standing
D. didn't know;Would stand
解析：句意：小心，你可能会掉进河里面。——谢谢你，我不知道。我站得离池子太近了。结合语境可知下文前一句指的是刚才的动作，故用一般过去时态。后一句指的是刚才一直在进行的动作，故用过去进行时态。选C。