会议期间他突然陷入一种清醒的恐惧，仿佛经历了一场白日噩梦。

During the meeting, he suddenly fell into a waking horror, as if experiencing a ___daymare.

她无法集中注意力，因为满脑子都是考试失败的幻想。

She couldn't focus because her mind was filled with ___daydreams about failing the exam.