Though , many laws of nature exist.
A. not having been discovered
B. having not been discovered
C. not having discovered
D. having not discovered
网友回答
(答案→)A. not having been discovered
B. having not been discovered
C. not having discovered
D. having not discovered
解析：连词加现在分词短语作状语；此句等于：Though the laws of nature have not been discovered