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.

[EX Q]: Sentence1: Scientists still know relatively little about Archaea. 
Sentence2: scientists still know relatively little about non-bacterial prokaryotes.
[EX A]: Scientists

[EX Q]: Sentence1: Ejaculation allows males to reproduce. 
Sentence2: propelling sperm from the epididymes allows males to reproduce.
[EX A]: allows

[EX Q]: Sentence1: vein deposits of gold and silver are formed by igneous intrusion. 
Sentence2: vein deposits of gold and silver are formed in higher elevations.
[EX A]:
deposits