This problem may more serious ones if left unsolved.
A. e across
B. refer to
C. carry on
D. lead to
网友回答
A. e across
B. refer to
C. carry on
(答案→)D. lead to
解析： 考查短语辨析。e across 偶然发现，refer to涉及，参考，carry on 继续，lead to 导致，句意：这个问题可能会导致更严重的问题如果留下不被解决的话。所以选D。