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: Stress is the applied force, strain is the change in shape. 
Sentence2: Paper is crumbled when stress and strain is applied in order to change the shape.
answer:
Stress


question:
Sentence1: the uterus is used in reproduction. 
Sentence2: Reproduction uses the same organ as menstruation.
answer:
reproduction


question:
Sentence1: Immunodeficiency occurs when the immune system is not working properly. 
Sentence2: Many cancers can cause immunodeficiency.
answer:

Immunodeficiency