请根据下面的短文内容判断句子，如果正确就填“T”,如果错误就填“F”,如果文中没有提到就填“N”。 People send birthday greetings by using cards in both eastern and western countries.It is not known when and where exactly the tradition of sending birthday cards began.It is believed that it began in England in the early nineteenth century.In those days people sent birthday cards when they couldn't wish somebody a happy birthday in person. In 1840 the first stamp was used in Britain and sending birthday cards became easier,cheaper and more popular.The development of color printing processes(工艺，流程)in the 1930s also helped to increase sales of birthday cards. Today cards are often given with a present,even when people can express their wishes face to face.In recent times e-cards have also become popular.Many people are starting to use e-cards instead of traditional cards because they are free,environmentally friendly and easy to arrive.So will e-cards take place of paper cards completely in ten or twenty years?Probably not.For example,for kids and old people,they don't use e-cards very often. If your birthday is coming soon,do you wish that at least one person could congratulate you with a beautiful card then?