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: faulting of rock in Earth 's crust causes earthquakes. 
Sentence2: fault movement forms earthquakes.

SOLUTION: earthquakes

PROBLEM: Sentence1: Some herbivores have more than one stomach. 
Sentence2: Camels are an herbivore.

SOLUTION: herbivores

PROBLEM: Sentence1: Mechanical energy can be converted into sound. 
Sentence2: an automobile engine transforms chemical energy into sound.

SOLUTION:
sound