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: Mating is generally preceded by courtship. 
Sentence2: Mating is generally similar across species.

SOLUTION: Mating

PROBLEM: 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.

SOLUTION: Streams

PROBLEM: Sentence1: Eggs are loaded with vitamins and minerals. 
Sentence2: eggs contain chemical elements that are essential for body processes.

SOLUTION:
Eggs