The transition word which is not correctly used in the passage is moreover.
As you can see in this sentence (<span>Moreover the invention of television and digital media, such as the Internet, most ads appeared in newspapers, magazines, and the radio.), something is wrong - the sentence doesn't sound natural or grammatical. This is why that word is the one which is used incorrectly, whereas the other sentences are good.</span>
Both inventions were done by teenagers at their times.
Both inventions claimed to help the environment: Boyan Slat's machine would clean up trash floating in ocean. Duro-Aina Adebola, Akindele Abiola, Faleke Oluwatoyin, and Bello Eniola proposed power generation from urine that would not create carbon monoxide.
Unfortunately both inventions were also challenged by more established scientists and engineers.
