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.

Q: Sentence1: Lymphocytes are the key cells involved in the immune response. 
Sentence2: The key cells involved in the immune response produce antibodies.

A: cells
****
Q: Sentence1: Germination depends on the seed coat. 
Sentence2: the force of water causes germination with the emergence of a root.

A: Germination
****
Q: Sentence1: All cnidarians are aquatic. 
Sentence2: Aquatic creatures live in the water, for example.

A:
aquatic
****