TASK DEFINITION: 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.
PROBLEM: Sentence1: Mammals depend on the vegetation for food and shelter. 
Sentence2: Mammals are Heterotrophs.

SOLUTION: Mammals

PROBLEM: 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.

SOLUTION: above

PROBLEM: Sentence1: Honey bees generate heat by consuming honey and shivering their muscles. 
Sentence2: Honey bees can shiver.

SOLUTION:
Honey