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

[EX Q]: Sentence1: If there is sun, there is sunlight, there is day. 
Sentence2: Energy enters ecosystems from the sun.
[EX A]: sun

[EX Q]: Sentence1: Antibiotics have no effect on viruses. 
Sentence2: Viruses are submicroscopic, cylindrical or spherical bodies.
[EX A]:
viruses