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: Angiosperm sporophyte is dominant. 
Sentence2: Flowers form on angiosperms.

SOLUTION: Angiosperm

PROBLEM: Sentence1: natural magnetism is used for pointing north by a compass. 
Sentence2: For the ordinary compass, align to the North direction.

SOLUTION: north

PROBLEM: Sentence1: Every season changes because the temperature changes with the seasons. 
Sentence2: earth being tilted on a rotating axis cause temperature changes.

SOLUTION:
changes