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: moss causes chemical weathering. 
Sentence2: Sphagnum moss mixed with peat moss.

A: moss
****
Q: Sentence1: Most bryophytes are small. 
Sentence2: Most in the same group as mosses are small.

A: small
****
Q: Sentence1: Invertebrates Among the invertebrates, the largest number of species are insects. 
Sentence2: Most insects have a complex nervous system.

A:
insects
****