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 generate heat mainly by keeping their metabolic rate high. 
Sentence2: food keeps mammals' metabolic rates high.

SOLUTION: Mammals

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

SOLUTION: Mammals

PROBLEM: Sentence1: intense heat has a negative impact on an organism. 
Sentence2: Bacteria are killed by intense heat for a certain time.

SOLUTION:
heat