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: Every photograph is produced by a camera. 
Sentence2: Photographers record images.
photograph

Sentence1: hurricanes convert heat energy into mechanical energy. 
Sentence2: Hurricanes use heat to move objects.
hurricanes

Sentence1: Beavers build dams that create ponds. 
Sentence2: Beavers cause ponds and lakes to form.

Beavers