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: Female monotremes lack a uterus and vagina. 
Sentence2: Babies are normally delivered from the uterus through the vagina.

A: uterus
****
Q: Sentence1: Most soil nutrients are cations. 
Sentence2: decomposition increases the amount of cations in the soil.

A: cations
****
Q: Sentence1: an electron microscope is used for seeing very small objects by making them appear bigger. 
Sentence2: Electrons are used to illuminate small objects and make them appear bigger.

A:
appear
****