【题目】They knew nothing about the war _______ they heard from the radio.
A.besides
B.except
C.except what
D.except for

【答案】C
【解析】考介词和介词短语。句意：除了从收音机中听到的，他们对战争一无所知。except “除…外没有”；besides“除…外还有”，从句中what做宾语指听到的内容，故选C。