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: Telephone Telephone calls are expensive. 
Sentence2: Communicating by transmitting sound is expensive.
answer:
expensive


question:
Sentence1: microbial fuel cells convert chemical energy into electrical energy. 
Sentence2: microbial fuel cells convert chemical energy into kinetic energy.
answer:
cells


question:
Sentence1: Bites from mosquitoes and other flying insects can cause pain and itching. 
Sentence2: Biting mosquitoes can spread disease and destroy crops.
answer:

Bites