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.

[EX Q]: Sentence1: a wildfire changes an ecosystem drastically. 
Sentence2: Forest fires change an ecosystem drastically.
[EX A]: changes

[EX Q]: Sentence1: when a river floods , that river deposits soil in flood plains. 
Sentence2: Hurricanes can cause local flooding, flash flooding, or coastal flooding.
[EX A]: flood

[EX Q]: Sentence1: Flowers produce spores that develop into gametophytes. 
Sentence2: Gametophytes are photosynthetic and often heart-shaped.
[EX A]:
gametophytes