Help a confused time-traveler from the 1800s write a letter home by matching each blank with the correct phrase.

People in this strange century stare at smartphones for hours without blinking. I am terrified of the metal carriages, especially since the cars on this specific street move so incredibly fast! They also claim that electricity is what powers everything instead of good old-fashioned coal.

People in this strange century stare at smartphones for hours without blinking.

We use the zero article for plural countable nouns when we are talking about them generally. The time-traveler means smartphones in general, not specific ones.

I am terrified of the metal carriages, especially since the cars on this specific street move so incredibly fast!

Because the time-traveler is talking about specific cars (the ones on this specific street), the definite article "the" is required.

They also claim that electricity is what powers everything instead of good old-fashioned coal.

"Electricity" is an uncountable noun. When speaking about it as a general concept, we use no article.