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: Graphite and diamond are polymorphs of carbon. 
Sentence2: carbon polymorphs are used for making pencil lead.
[A]: carbon


[Q]: Sentence1: Passive immunity lasts only as long as the antibodies survive in body fluids. 
Sentence2: A pregnant woman will pass antibodies to the fetus.
[A]: antibodies


[Q]: Sentence1: the vomiting reflex is used to remove toxic material from the stomach before it is absorbed. 
Sentence2: loss of balance are results of toxic material in the stomach.
[A]:
material