Complex sentence: According to Deckard, a normal replicant can usually be discovered using the Voight-Kampff test after being given about 20-30 questions, cross-referenced, but Rachael answered over 100 questions before Deckard realized she was a replicant.
Split into simpler sentences: According to Deckard, a normal replicant can usually be discovered using the Voight-Kampff test after being given about 20-30 questions, cross-referenced. However, Rachael answered over 100 questions before Deckard realized she was a replicant.