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: Visible and invisible light is energy in the form of electromagnetic waves. 
Sentence2: Eyes are used for seeing animals by sensing electromagnetic waves.

SOLUTION: electromagnetic

PROBLEM: Sentence1: An organism can gain energy by assimilation or absorption of food. 
Sentence2: Organisms require food for growth.

SOLUTION: food

PROBLEM: Sentence1: Pulley A pulley makes work easier by changing direction of the force applied. 
Sentence2: Heavy objects are lifted by changing the direction of force.

SOLUTION:
changing