Someone help me pls I’m tryna get a high score

I think it's The pony allowed for faster communication in the rapidly growing united states.

summary - a brief statement or account of the main points of something.

main idea - the main idea is defined as the main point of a speech or piece of writing.

paragraph - a distinct section of a piece of writing, usually dealing with a single theme and indicated by a new line, indentation, or numbering.

showing or suffering from nervousness, fear, or a lack of confidence