TASK DEFINITION: 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.
PROBLEM: Sentence1: wind is used for producing electricity. 
Sentence2: Wind is caused because of pressure differences in the atmosphere.

SOLUTION: wind

PROBLEM: Sentence1: Lions live in social groups called prides. 
Sentence2: Chimpanzees live in social groups called communities.

SOLUTION: groups

PROBLEM: Sentence1: Sex cells, also called gametes, are the sperm in males and the ova in females. 
Sentence2: A mutation in the gametes of a parent can cause a new trait to appear in the parent 's offspring.

SOLUTION:
gametes