There's a feeling in me ________ we'll never know what a UFO is-not ever．

A.that

B.which

C.of which

D.what

答案及解析： A

同位语从句that we'll never know what a UFO is-not ever作a feeling的同位语，解释a feeling的具体内容．that连接同位语从句时，只起连接作用，不作从句的任何成分．