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: Climate Forests stabilize climate. 
Sentence2: forests stabilize what is generally described in terms of temperature and moisture.

A: Forests
****
Q: Sentence1: a flashlight requires a source of electricity to produce light. 
Sentence2: Flashlights provide the safest emergency lighting source.

A: flashlight
****
Q: Sentence1: Sexual reproduction involves sperm and an egg. 
Sentence2: adult sponges reproduce sexually.

A:
Sexual
****