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.

Sentence1: when a river floods , that river deposits soil in flood plains. 
Sentence2: when a river floods, it deposits soil in generally marshy areas.
deposits

Sentence1: if fossils of an animal or plant are found in a place then that animal or plant used to live in that place. 
Sentence2: Fossils are preserved original remains or preserved evidence of plants and animals.
fossils

Sentence1: Chromosomes contain genes, which code for proteins. 
Sentence2: Protein builds and repairs body tissue.

proteins