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: healing requires rest. 
Sentence2: Healing and cell regeneration follows.

A: healing
****
Q: Sentence1: if an organism becomes too hot then that organism may die. 
Sentence2: if an organism overheats then that organism may die.

A: die
****
Q: Sentence1: when a plant grows , the size of the leaves of that plant may increase. 
Sentence2: Ferns are vascular plants.

A:
plant
****