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.

Sentence1: Ions are atoms or groups of atoms that carry a positive or negative electrical charge. 
Sentence2: An ion is formed after a neutral atom loses an electron.
Ions

Sentence1: Among monogamous species of birds and mammals, both parents often care for their offspring. 
Sentence2: The period of parental care after birth for manogamous species are handled by both parents.
monogamous

Sentence1: being burried under soil and mud changes vegetation into peat through extreme heat and pressure in a swamp over a long period of time. 
Sentence2: Peat moss from bogs is also useful in gardens and as an alternative fuel source.

peat