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: Mammals depend on the vegetation for food and shelter. 
Sentence2: Mammals are Heterotrophs.
Mammals

Sentence1: igneous rocks are formed from magma cooling. 
Sentence2: magma solidifies into igneous rocks.
magma

Sentence1: a magnet moving in a coil of copper wire can cause an electric current. 
Sentence2: a magnet moving in a coil of copper can cause a flow of electrons.

cause