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: When we increase the temperature of objects, they always expand.

A: increase
****
Q: Sentence1: a mutation in the sex cells of a parent can cause a new trait to appear in the parent 's offspring. 
Sentence2: cancer of a parent's cells can cause a new trait to appear in their offspring.

A: appear
****
Q: Sentence1: if a habitat can no longer support animals then those animals will move to another area. 
Sentence2: Environmentalists say forest roads add to erosion, destroy habitat and affect animal migration.

A:
habitat
****