There’s a feeling in me we’ll never know what a UFO is – not ever. A. of whichB. whichC.

问题补充：

There’s a feeling in me we’ll never know what a UFO is – not ever.

A. of which

B. which

C. that

D. what

答案：

A. of which

B. which

(答案→)C. that

D. what

解析：句意：我有种感觉，我们将永远都不知道不明飞行物到底是什么东西。这里是that引导的同位语从句，它在从句中不作成分，先行词是feeling，同位语从句that we’ll never know what a UFO is – not ever.来解释它的内容，其他的连词必须在同位语从句中做成分，而这里不缺少成分，故选C。