instruction:
Generate an overlapping word between the given two sentences. When you find the overlapping words, they don't have to match exactly, e.g., "survival" and "survive" are valid overlapping words. Little words like "the" or "of" don't count! You must generate significant words which are not the stop words.
question:
Sentence1: a mutation in the sex cells of a parent can cause a new trait to appear in the parent 's offspring. 
Sentence2: cancer of a parent's cells can cause a new trait to appear in their offspring.
answer:
appear


question:
Sentence1: Enveloped viruses make their own membranes. 
Sentence2: Some viruses make their own membranes.
answer:
make


question:
Sentence1: Light enters the eye through an opening called the pupil. 
Sentence2: Photons enter the eye through the pupil.
answer:

pupil