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: Macroevolution occurs over geologic time above the level of the species. 
Sentence2: adding new genes with special capability occurs over geologic time above the level of the species.
above

Sentence1: Basically the process is pretty simple. 
Sentence2: All cells share some of the same structures and simple processes.
process

Sentence1: Osteoporosis is a disease in which osteoclasts are more active than osteoblasts. 
Sentence2: thinning and weakening of bone occurs when osteoclasts are more active than osteoblasts.

active