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: rain causes erosion. 
Sentence2: Soil Erosion Soil erosion is what happens when soil is washed or blown away.
erosion

Sentence1: If there is no movement friction is zero. 
Sentence2: Movement causes the temperature of an object to increase.
movement

Sentence1: Communities consist of populations of different species. 
Sentence2: Wetlands consist of populations of herons and different species.

consist