In 1847 most countries of the world were ______.
A. not yet using postage stamps
B. collecting valuable stamps
C. buying stamps from Neuritis
D. printing their own stamps
正确答案：A
此题为理解题从文中第3段最后一句．．．Mauritiuswastobecomethefourthcountryintheworldtoissuestamps可知当时世界上使用邮票的国家并不多故A为正确答案
