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: air pollution can cause the pH of soil to decrease. 
Sentence2: Acidity is measured with a pH meter or with pH paper strips.

SOLUTION: pH

PROBLEM: Sentence1: Flies are insects with two wings. 
Sentence2: Flies are arthropods with two wings.

SOLUTION: Flies

PROBLEM: Sentence1: some light bulbs convert electricity into light and heat energy. 
Sentence2: Halogen bulbs convert electricity into heat.

SOLUTION:
convert