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: Fractures heal when osteoclasts form new bone. 
Sentence2: Fractures A fracture is a broken or cracked bone.
[A]: Fractures


[Q]: Sentence1: Runoff water is wasted water. 
Sentence2: Streams may start with wasted water.
[A]: wasted


[Q]: Sentence1: Microevolution leading to macroevolution, discussed earlier, is one example. 
Sentence2: Microevolution happens over time.
[A]:
Microevolution