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: Streams may start with runoff or water seeping out of a spring. 
Sentence2: streams may start with runoff or h2o seeping out of a spring.
[A]: Streams


[Q]: Sentence1: Cancer is a disease in which cells divide out of control. 
Sentence2: Cancer is a disease in which cells grow and divide rapidly.
[A]: Cancer


[Q]: Sentence1: Sporangia produce spores that develop into tiny, heart-shaped gametophytes. 
Sentence2: All gametophytes are haploid.
[A]:
gametophytes