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: Specialization decreases mortality 12,13 and increases survival. 
Sentence2: evolving different adaptations increases survival.

A: increases
****
Q: Sentence1: Boiling water can cause burns. 
Sentence2: heating water can cause burns.

A: water
****
Q: Sentence1: Trees have woody stems covered with bark. 
Sentence2: On the outside is a protective skin of bark made mainly of cork.

A:
bark
****