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
网友回答
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。