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: Plants exhibit phototropism, or growing toward a light source. 
Sentence2: Phototropism means growing toward the energy of light.
answer:
phototropism


question:
Sentence1: Earth's Atmosphere Earth's atmosphere is the layer of gasses that surrounds the earth. 
Sentence2: weather refers to the conditions in the layer of gasses that surrounds the earth.
answer:
earth


question:
Sentence1: Hormones control many cell activities, so they are very important for homeostasis. 
Sentence2: Many of the processes of homeostasis are mediated by hormones.
answer:

Hormones