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.

Q: Sentence1: when a hemisphere is tilted away from the sun , that hemisphere receives less direct sunlight. 
Sentence2: Sunlight is delivered in small packets of energy called photons.

A: sunlight
****
Q: Sentence1: Dromaeosaurs are part of the theropod group of dinosaurs. 
Sentence2: Birds evolved from a group of bipedal dinosaurs that included Dromaeosaurs.

A: Dromaeosaurs
****
Q: Sentence1: photosynthesis means producers convert from carbon dioxide, water, and solar energy into carbohydrates for themselves. 
Sentence2: Leaf cells produce sugar by photosynthesis.

A:
photosynthesis
****