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.

Sentence1: If there is enough moisture in the clouds, rain is produced. 
Sentence2: Clouds lacking water reduces rainfall.
clouds

Sentence1: Lancelet larvae are free-swimming. 
Sentence2: some larvae lack a hardened backbone.
larvae

Sentence1: Coral reefs provide food and shelter to many ocean organisms. 
Sentence2: Patch reef provide food and shelter to many ocean organisms.

food