Given the task definition and input, reply with output. In this task, you are given dialogue, and you have to find the most critical location in the given conversation.

Hi, I want to learn about United States Infrastructure?
Hello. As of 2007 China is the only country whose total greenhouse gas emissions exceed those of the United States.
Do you happen to know the percentage China exceeds US?
I'm sorry, I don't have any specific percentage.
What else can you educate me on its infrastructure?
Well, the Transportation Security Administration was created in the aftermath of the 2001 terrorist attacks to police airports and commercial airliners.
Thanks. I want to learn about Etymology?
The phrase "United States of America" was first published in an anonymous essay on April 6, 1776 in The Virginia Gazette newspaper.
I didn't know that, do you what the meaning behind the name"United States"?
Yes, it means each state in America is united under one federal government.
Great. Whats else can you tell me about its etymology?
"American" in the English language usually relates to topics or subjects connected with the United States even though the "Americas" also include Canada, Central, and South America.
Thanks a lot.
You're most welcome!
United States