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: If there is sun, there is sunlight, there is day. 
Sentence2: Energy enters ecosystems from the sun.
answer:
sun


question:
Sentence1: Genetics is the study of inheritance. 
Sentence2: Pedigrees are useful tools for studying genetics.
answer:
Genetics


question:
Sentence1: mineral graphite is used for making pencil lead. 
Sentence2: F.Y.I., graphite is known as a semimetal.
answer:

graphite