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: An electric current is a flow of electric charge. 
Sentence2: a magnet moving in a coil of copper wire can cause a flow of electric charge.

SOLUTION: charge

PROBLEM: Sentence1: Mammals that are viviparous are called therian mammals. 
Sentence2: Mouse-sized viviparous mammals evolved by Jurassic times.

SOLUTION: Mammals

PROBLEM: Sentence1: Inside a greenhouse, it is the glass roof that creates the warmth. 
Sentence2: glass can protect plants from cold.

SOLUTION:
glass