Question

Circle Ud. or tú to indicate how you would address the person being spoken to.*

Answer 1

"Answer:

Tu: "Buenos tardes, profesor!

Usted: Buenos Dias, Luis.

Tu: Hola, Sr. Gómez.

Usted: "¿Cómo estás, Paco?

Tu:  "Adiós, señora."

I believe this is the order it will go

Answer 2

1. Usted
2. Tu
3. Tu
4. Usted
5. Usted

Tu - is used when you know the person and have a lot of confidence. Usted is used to refer to people to whom you should treat them with more respect.