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: Crops are plants that are grown for food or other uses. 
Sentence2: insects destroy plants.

SOLUTION: plants

PROBLEM: Sentence1: All chemical reactions require activation energy to get started. 
Sentence2: Catalysts lower the activation energy.

SOLUTION: activation

PROBLEM: Sentence1: Bioterrorism is another potential threat in the environment. 
Sentence2: Another potential threat to the environment is the potential release of anthrax.

SOLUTION:
another