TASK DEFINITION: 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.
PROBLEM: Sentence1: Finally, the fluid in the nephron reaches a collecting duct . 
Sentence2: fluid in the kidneys collect into ducts.

SOLUTION: fluid

PROBLEM: Sentence1: Silica sand is primarily mined from sandstone deposits. 
Sentence2: erosion forms silica sand.

SOLUTION: Silica

PROBLEM: Sentence1: sediment is formed by weathering. 
Sentence2: Sand is an example of a clastic sediment.

SOLUTION:
sediment