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: Osteoporosis is a disease in which osteoclasts are more active than osteoblasts. 
Sentence2: a thinning and weakening of bone is a disease in which osteoclasts are more active than osteoblasts.
[A]: active


[Q]: Sentence1: Bivalves feed on plankton and nonliving organic matter. 
Sentence2: Clams feed on plankton and nonliving organic matter.
[A]: feed


[Q]: Sentence1: rest has a positive impact on a health. 
Sentence2: Bottom line indicates at rest or sleep.
[A]:
rest