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: Very often their only metal object in the house is a cooking pot or a knife. 
Sentence2: sharpening a knife causes it to change shape.

SOLUTION: knife

PROBLEM: Sentence1: Weather Clear weather usually means good visibility. 
Sentence2: High pressure systems can cause good visibility.

SOLUTION: good

PROBLEM: Sentence1: All plants are of bush type. 
Sentence2: bushes use cellulose for their cell walls.

SOLUTION:
bush