I read from die out to diet.

Differentia differentiates one thing from another. 

https://en.wikipedia.org/wiki/Genus%E2%80%93differentia_definition

https://en.wikipedia.org/wiki/Differentia

The "differential drive train" makes the car go in different ways.

https://en.wikipedia.org/wiki/Differential_(mechanical_device)

The formulas in "differential calculus" hurt my brain.

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