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.

[EX Q]: Sentence1: Dromaeosaurs are part of the theropod group of dinosaurs. 
Sentence2: Birds evolved from a group of bipedal dinosaurs that included Dromaeosaurs.
[EX A]: Dromaeosaurs

[EX Q]: Sentence1: if an object in a fluid is more dense than that fluid then that object will sink in that fluid because of gravity. 
Sentence2: Most seeds are more dense than water.
[EX A]: dense

[EX Q]: Sentence1: Antigens are molecules that the immune system recognizes as foreign to the body. 
Sentence2: the immune system can recognize cancer as foreign to the body.
[EX A]:
body