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: Muscles can only contract. 
Sentence2: Contraction is a type of movement.

SOLUTION: contract

PROBLEM: Sentence1: a flashlight converts chemical energy into light energy. 
Sentence2: Only as long as there are batteries in the flashlight, the flashlight will function.

SOLUTION: flashlight

PROBLEM: Sentence1: Ants communicate with chemicals called pheromones. 
Sentence2: Ants communicate with the colony in the form of what is called pheremon trails.

SOLUTION:
Ants