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: Lancelet larvae are free-swimming. 
Sentence2: some larvae lack a hardened backbone.

SOLUTION: larvae

PROBLEM: Sentence1: a flashlight converts chemical energy into light energy. 
Sentence2: PALight Flashlights are the ultimate personal LED flashlights.

SOLUTION: flashlight

PROBLEM: Sentence1: Blood pressure is highest in arteries and lowest in veins. 
Sentence2: Blood moves slowly and with very little pressure in veins.

SOLUTION:
Blood