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: Carbon dioxide is controlled by the carbon cycle. 
Sentence2: Carbon dioxide is controled by the carbon circle and is transferred between organisms and atmosphere.
[A]: controlled


[Q]: Sentence1: when a body of water receives more water than it can hold , a flood occurs. 
Sentence2: Floods are deadly, floods are devastating.
[A]: flood


[Q]: Sentence1: Mutations may change the structure of a chromosome or just change a single nucleotide. 
Sentence2: Changes in the structure of the Y chromosome are implicated in male infertility.
[A]:
change