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.

[EX Q]: Sentence1: Dams are very damaging to rivers. 
Sentence2: Creating a lake can be very damaging to rivers.
[EX A]: damaging

[EX Q]: Sentence1: Bound and free ribosomes are structurally identical and interchangeable. 
Sentence2: Bound and free structures are in the cytoplasm where proteins are made.
[EX A]: Bound

[EX Q]: Sentence1: Appearance nodes affect an object's appearance, such as color, material properties, or texture maps. 
Sentence2: An object made with a material will have the appearance, texture and color of the material.
[EX A]:
appearance