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: Most bryophytes are small. 
Sentence2: Most in the same group as mosses are small.

A: small
****
Q: Sentence1: Water erosion has similar consequences as wind erosion. 
Sentence2: exposure to water can cause erosion.

A: Water
****
Q: Sentence1: Adaptation and natural selection are discussed. 
Sentence2: Evolution occurs by a process of adaptation.

A:
Adaptation
****