Why do HTTP, SMTP, and POP3 run on top of TCP rather than UDP?

The text below shows the reply sent from the server in response to the HTTP GET message in the question above. Answer the following questions, indicating where in the message below you find the answer.

HTTP/1.1 200 OKDate: Tue, 07 Mar 2008 12:39:45GMTServer:

Apache/2.0.52 (Fedora)Last-Modified: Sat, 10 Dec2005 18:27:46 GMTETag: 526c3-f22-a88a4c80Accept-Ranges: bytesContent-Length: 3874 Keep-Alive: timeout=max=100Connection:Keep-AliveContent-Type: text/html; charset=ISO-8859-1

Was the server able to successfully find the document or not? What time was the document reply provided?

When was the document last modified?

How many bytes are there in the document being returned?

What are the first 5 bytes of the document being returned? Did the server agree to a persistent connection?