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: Runoff water is wasted water. 
Sentence2: Streams may start with wasted water.

SOLUTION: wasted

PROBLEM: Sentence1: Minerals are chemical elements that are essential for body processes. 
Sentence2: Eggs are loaded with vitamins and minerals.

SOLUTION: Minerals

PROBLEM: Sentence1: Hydrogen ions are equivalent to acidity. 
Sentence2: Hydrogen ions change the color of litmus paper from blue to red.

SOLUTION:
Hydrogen