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: if a habitat can no longer support animals then those animals will move to another area. 
Sentence2: Each species of animal is unique.

SOLUTION: animals

PROBLEM: Sentence1: measuring the hardness of minerals requires scratching those materials. 
Sentence2: To figure out the hardness of a mineral, the Moh's scale of hardness is used.

SOLUTION: minerals

PROBLEM: Sentence1: Reproduction is the process by which living things give rise to offspring. 
Sentence2: Reproduction is the process by which genes are passed.

SOLUTION:
Reproduction