A、In 1840. B、In 1820. C、In 1804. D、In 1890. A对话中男士说“You know，the first postagestamps were issued in Britain in 1840”，故选A。

W: When did you become interested in collecting stamps?
M: Oh, when I was about ten years old. It’s an exciting hobby.(18)You know, the first postage stamps were issued in Britain in 1840.
W: Really? I didn’t know that.(19)I did know that the charge for mail delivery before the appearance of postage stamps was paid by either the sender or the receiver. How much was the usual charge?
M: Oh, about ten cents for a short distance. But post offices were losing money with that system Rowland Hill, an Englishman, suggested using postage stamps. Here’s a picture of the first two stamps issued.
W: They both bear a picture of Queen Victoria.
Q18: When were the first postage stamps issued?
Q19: Who paid for the mail delivery before the appearance of postage stamps?