3．You can buy chewing gum in nearly every country of the world．①But it wasn't always like that． The American Indians were the first people to chew gum．Thisgum came from a special tree that grew on their land．In 1848，a sailor called John Curtis began selling it．He was the first person to sell chewing gum．The gum he sold cost just a few cents for two pieces．It became popular very quickly even though it was very hard to chew． ②Nowadays，other things are added to the gum to make it soft and sweet． By 1890，there were hundreds of different chewing gums．The most famous name in chewing gum，however，is probably William Wrigley．He spent a lot of money in advertising and even sent free pieces of gum to children on their birthdays．③He also said that chewing gum helped people work better and that it stopped people from feeling tired． Although today many millions of people chew gum，not everyone thinks it is a good thing to do．Many people think it is dirty． The Singapore government does not allow people to buy chewing gum．One reason for this is that when some people have chewed all the taste out of their piece of gum，they take it out of their mouths and put it on to the backs of seats or other places． 71．请将①处翻译成汉语．但是过去并非如此． 72．请根据②处内容完成下面句子．（每空一词） People make chewing gum soft and sweetbyaddingsomething to it． 73．把③处改为直接引语．（每空一词） He also said"，Chewing gumhelps people work better and itstops people from feeling tired．"
