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: Mollusks live in most terrestrial, freshwater, and marine habitats. 
Sentence2: Clams live in freshwater habitats.
[A]: freshwater


[Q]: Sentence1: An accounting period is simply a period of time. 
Sentence2: seconds are used to measure a period.
[A]: period


[Q]: Sentence1: if humans disturb animals in a location then those animals will move to a different location. 
Sentence2: Controlling development controls human disturbances of the river bank and its watershed that can increase erosion, disturb animal habitat and consequently, impair water quality.
[A]:
disturb