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: friction causes the temperature of an object to increase. 
Sentence2: internal combustion engines get hot.
[A]: temperature


[Q]: Sentence1: a stopwatch is used to measure time. 
Sentence2: Time can be measured with a clock or watch.
[A]: measure


[Q]: Sentence1: rocks interacting with wind over long periods of time causes weathering. 
Sentence2: When a rock undergoes erosion and weathering, it breaks down to form sediments.
[A]:
weathering