问题补充：
Japan’s nuclear crisis (核危机) will be solved in is not known yet.
A. That
B. If
C. Whether
D. What
答案：
A. That
B. If
(答案→)C. Whether
D. What
解析：考查主语从句。 Japan’s nuclear crisis (核危机) will be solved in 在主从复合句 Japan’s nuclear crisis (核危机) will be solved in is not known yet中作主语。根据is not known yet，还不知道，可知主语从句表不确定，应由Whether引导，If不能引导主从。所以选C。
