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: the mass of a planet causes the pull of gravity on that planet. 
Sentence2: the mass of a planet is what causes things to have weight.
[A]: mass


[Q]: Sentence1: rain causes erosion. 
Sentence2: Soil Erosion Soil erosion is what happens when soil is washed or blown away.
[A]: erosion


[Q]: Sentence1: Plasma is more common in stars, because making plasma requires high temperatures. 
Sentence2: Plasma is formed in high temperatures of the sun.
[A]:
high