In the last 500 years, nothing about people-not their clothes, ideas, or languages has changed as much as what they eat．The original chocolate drink was made from the seeds of the cocoa tree(可可树) by South American Indians．The Spanish introduced it to de rest of the world during the 1500s．And although it was very expensive, it quickly became fashionable．In London, shops where chocolate drinks were served became important meeting places．Some still exist today.
The potato is also from the New World．Around 1600, the Spanish brought it from Peru to Europe, where it soon was widely grown．(78) Ireland became so dependent on it that hundreds of thousands of Irish people starved when the crop failed during the 'Potato Famine(饥荒)'of 1845-1846, and millions more were forced to leave their homeland and move to North America．
There are many other foods that have traveled from South America to the Old World．But others went in the opposite direction．Brazil is now the world's largest grower of coffee, and coffee is an important crop in Colombia and other South American countries．But it is native to Ethiopia, a country in Africa．Coffee was first made into a drink by Arabs during the 1400s.
(79) According to an Arabic legend, coffee was discovered when a person named Kaldi noticed that his goats were attracted to the red berries on a coffee bush．He tried one and experienced the 'wide-awake' feeling that one-third of the world's population now starts the day with.
According to the passage, which of the following has changed the most in the last 500 years?