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: If there is an increase in UV radiation, the risks go up for all types of skin cancer. 
Sentence2: Ozone depletion increases the risks for all types of skin cancer.
all

Sentence1: Light source is an ultra-bright, unbreakable LED Bulb. 
Sentence2: LEDs convert electricity into light and heat energy.
LED

Sentence1: travelling requires navigation. 
Sentence2: Navigation takes a bit of getting used to.

navigation