It remains to be seen North Korea will remain stable under its new young leader.
A. when
B. whether
C. why
D. That
网友回答
A. when
(答案→)B. whether
C. why
D. That
解析：考查固定句型。It remains to be seen whether...“......还有待观察”，it是形式主语，真正的主语是whether引导的主语从句。句意：朝鲜在新的年轻领导人领导下，能否保持安定，还有待观察。故选B。