How can a small stamp be worth ＄16,800?
Any mistake made in the printing of a stamp raises its value to stamp collectors. A mistake on a two-penny stamp has made it worth a million and a half times its face value.
Do you think it impossible? Well, it is true. And this is how it happened.
The mistake was made more than a hundred years ago in the former British colony (前英国殖民地) of M auritius (毛里求斯岛), a small island in the Indian Ocean. In 1847 an order for stamps was sent to London. Mauritius was about to become the fourth country in the world to put out stamps.
Before the order was filled and the stamps arrived from England, a big dance was planned by the commander-in-chief (总司令) of all the armed forces on the island. The dance would be held in his house and letters of invitation would be sent to all the important people in Mauritius. Stamps were badly needed to post the letters. Therefore, an islander, who was a good printer, was told to copy the pattern of the stamps. He carelessly put the words “Post Office” instead of “Post Paid”, two words seen on stamps at that time, on the several hundred that he printed.
Today, there are only twenty-six of these misprinted stamps left--- fourteen One-penny Reds and twelve Two-penny Blues. Because there are so few Two-Penny Blues and because of their age, collectors have paid as much as ＄16,800 for one of them.
When a mistake is made in the printing of the stamp, the stamp___________.

A．will be thrown away

B．increases in value

C．is not worth buying

D．is worth no more than its face value

Why did Mauritius print some stamps too? Because__________.

A．London stamps were not well printed

B．London would not print them

C．invitations to a big dance had to be posted quickly

D．Mauritius had a very good printer

“Post Paid” means___________.

A．the same as “Post Office”

B．the Post Office is the place to buy stamps

C．money has been paid for the stamp

D．the letter must be posted