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: Runoff water is wasted water. 
Sentence2: Streams may start with wasted water.
wasted

Sentence1: Protozoa make humans sick when they become human parasites. 
Sentence2: paramecium are single celled animals that make humans sick when they become human parasites.
become

Sentence1: when a gas in an open container evaporates , that gas spreads out into the air. 
Sentence2: Evaporation is when a liquid turns into a gas.

evaporates