the flight to Beijing will be delayed is I’m especially worried about.
A. If; what
B. Whether; that
C. When; that
D. Whether; what
网友回答
A. If; what
B. Whether; that
C. When; that
(答案→)D. Whether; what
解析： 考查主语从句和表语从句。句意:是否去北京的航班回推迟是我特别担忧的事。第二空缺宾语故用what。所以选D。