A、In 1840. B、In 1820. C、In 1804. D、In 1890. A对话中男士说“You know，the first postage stamps 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?