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: Ejaculation allows males to reproduce. 
Sentence2: propelling sperm from the epididymes allows males to reproduce.

SOLUTION: allows

PROBLEM: Sentence1: Plants exhibit phototropism, or growing toward a light source. 
Sentence2: Bamboos are vigorous, rugged plants.

SOLUTION: Plants

PROBLEM: Sentence1: conserving resources has a positive impact on the environment. 
Sentence2: Recycling saves energy, conserves natural resources and helps protect the environment.

SOLUTION:
conserving