单项选择题
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 sent it by registered mail. It’s more expensive, but it’s the safest way.
A. A valuable book.
B. An important certificate.
C. A beautiful postcard.
D. An application form.