____ the flight to New York will be delayed is ____ I'm especially worried about.A．If; whatB．Whether; thatC．When; thatD．Whether; what

____ the flight to New York will be delayed is ____ I'm especially worried about.
A．If; whatB．Whether; thatC．When; thatD．Whether; what

第一空填whether,连接主语从句,第二空填what,连接的是宾语从句,what在宾语从句中做宾语,选D.