— I've just heard    about that the lecture given by Guo Feng,a young doctor,    was cancelled.    

— Oh, no!  _____  .    [ ]

A. It's wonderful    

B. It doesn't matter    

C. I have no idea    

D. I was looking forward to that

水体下采煤，（）是从开采上限到上覆水体底界面之间的煤层、岩层和松散层的总称。