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: Light is the visible form of electromagnetic energy. 
Sentence2: Electromagnetic energy enters the eye through an opening called the pupil.
[A]: electromagnetic


[Q]: Sentence1: a tape measure is used to measure length. 
Sentence2: Length The Base unit for length in the metric system is the meter .
[A]: length


[Q]: Sentence1: Most fish breathe through gills. 
Sentence2: fish get oxygen in water from gills.
[A]:
fish