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.

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.
controlled

Sentence1: disease-causing microbes have a negative impact on the body. 
Sentence2: pathogens have a negative impact on the body.
body

Sentence1: Earthquakes and volcanoes are violent proof of Earth's shifting crust. 
Sentence2: Faulting of rock in the Earth causes a shifting crust.

crust