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: Germination depends on the seed coat. 
Sentence2: the force of water causes germination with the emergence of a root.

SOLUTION: Germination

PROBLEM: Sentence1: Methane gas is a produced by rotting compost, trash, and human waste. 
Sentence2: Methane gas can be produced by Slime molds.

SOLUTION: Methane

PROBLEM: Sentence1: Many corals secrete an exoskeleton that builds up to become a coral reef. 
Sentence2: Corals construct an exoskeleton by secreting calcium  carbonate.

SOLUTION:
corals