Answer:
Fluids
Explanation:
Liquids and gases are called fluids because they can be made to flow, or move.
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>