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: Muscles can only contract. 
Sentence2: Contraction is a type of movement.
answer:
contract


question:
Sentence1: Endocrine glands include the pituitary, thyroid, parathyroid, adrenal, pineal and thymus glands. 
Sentence2: Some pituitary hormones can control the thyroid gland.
answer:
thyroid


question:
Sentence1: Lakes are generally bigger and deeper than ponds. 
Sentence2: Lakes are generally bigger and deeper than where frogs start out life.
answer:

Lakes