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.

[Q]: Sentence1: if an object is made of a material then that object has the properties of that material. 
Sentence2: items properties are the same as the materials the item is made of.
[A]: made


[Q]: Sentence1: Mitosis is cell division. 
Sentence2: mitosis often causes growth.
[A]: Mitosis


[Q]: Sentence1: when metal conducts heat , that metal expands. 
Sentence2: metal contracts when it cools.
[A]:
metal