Given the question "What is in the letter?" and the answer "An important certificate.", write a conversation that might have happened.
A:
M: I want to make sure my son receives this letter. It has an important certificate in it.W: You can send it either by certified mail or registered mail. If you only want to make sure it is received, send it by certified mail. It's less expensive.M: OK. How about this package?W: What's in it?M: A watch.W: You should insure it for the value of the watch, and send it by registered mail. It's more expensive, but it's the safest way.