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: poisonous darts are used for defense by sea anemones. 
Sentence2: poisonous darts are used for protection by sea anemones.

SOLUTION: anemones

PROBLEM: Sentence1: Water is essential for all life on Earth. 
Sentence2: H2O is needed for all life on Eartth.

SOLUTION: Earth

PROBLEM: Sentence1: Recycling means reusing things. 
Sentence2: Reusing things has a positive impact on the environment.

SOLUTION:
reusing