他们几乎察觉不到远处微弱的光。

They could barely ___perceive a faint light in the distance.

我以为我能透过窗帘察觉到一丝微弱的光。

I thought I could ___perceive a faint light through the curtains.

只有经过训练的耳朵才能察觉到这两段录音之间的细微差别。

Only a trained ear could ___perceive the subtle difference in the two recordings.