instruction:
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.
question:
Sentence1: Sperm pass out of the body through the urethra. 
Sentence2: Sperm travel from the testicles through the vas deferens to the seminal vesicles and the prostate.
answer:
Sperm


question:
Sentence1: Human mating behavior also involves some competition. 
Sentence2: Human mating may lead to aggressive behaviors or displays of aggresion.
answer:
Human


question:
Sentence1: The nature of sunlight Sunlight is electromagnetic energy. 
Sentence2: For plants to photosynthesize, they require electromagnetic energy.
answer:

electromagnetic