阅读下面短文，按照句子结构的语法性和上下文连贯的要求，在空格处填入一个适当的词或使用括号中词语的正确形式填空，并将答案填写在答题卡标号为16—25的相应位置上。
Although it could not compete with the speed of email today, the 1800’s experienced a revolution in communication that played an important role in creating the tradition of the Christmas greeting card. ____(help) by the new railway system, the public postal service made corresponding a popular past time. In England, Sir Henry Cole recognized the advantage of ___more efficient mail service and initiated (开始) the practice of sending Christmas greeting cards ____ friends. 
The first card ____ (design) by J.C. Horsley as a commercial endeavor(尝试,努力). One thousand copies were sold in London, ____ soon others followed suit. An English __ (art), William Egley, produced a popular card in 1849. Louis Prang, a German born printer, working from ___ shop in Massachusetts, printed his first American cards in 1875. Even more ____ (importance) than his printing was the fact ___ he did more than anyone else to popularize the cards by instituting nationwide contests for the best Christmas designs, ___ were awarded cash prizes.