单选题 In the last 500 years, nothing about people-their clothes, ideas, or languages-haschanged as much as what they eat. The original chocolate drink was made from the seeds of cocoa tree by South American Indians. The Spanish introduced it to the rest of the world during the 1500's. Although it was very expensive, it quickly became fashionable. In Lon-don, 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. The potato was the main food at Irish table. Thousands of Irish people starved when the crop failed during the "Potato Famine"(土豆饥荒) of 1845～1846, and thousands more were forced to move to America.
There are many other foods that have traveled from South America to the old World. But some 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 (埃塞俄比亚). It was first made into a drink by Arabs during the 1400's.
(77) According to an Arabic story, coffee was discovered when a man named Kaldi noticed that his goats were attracted to the red fruits on a coffee bush. (78) He tried one and experienced the "wide-awake" feeling that one-third of the world's population now starts the day with.

单选题 According to the passage, which of the following has changed the most in the last 500 years?
【正确答案】 A
【答案解析】文章开头便指出在过去的500年，关于人类的一切东西都在不断变化，而food(食物)是变化最为显著的。B、C、D三项都属于食物。
单选题 "Some" in the sentence "Some still exist today. " refers to ______.
【正确答案】 C
【答案解析】In London，shops where chocolate drinks were served became impor-tant meeting places．Some still exist today．第二句some指的是第一句的主语，所以应选C。
单选题 Thousands of Irish people starved because______.
【正确答案】 D
【答案解析】文中第二段指出，土豆是爱尔兰人的主要食物。Thousands of Irish people Starved when the crop failed during the“Potato Famine”of 1845～1846．爱尔兰人的饥荒是因为他们赖以生存的食物——土豆的歉收。A项是事实，但不是原因。B项是结果。C项文中没有提到。
单选题 Coffee originally came from ______.
【正确答案】 C
【答案解析】文章的第三段有明确的一句：But it is native to Ethiopia．be native to是“起源于，原产于”的意思。
单选题 The writer used an Arabic story to prove that______.
【正确答案】 D
【答案解析】文章的第三段说咖啡虽然广泛种植于南美国家，但它其实起源于埃塞俄比亚，并首先被阿拉伯人制成饮料。为了证明这一点，下一段给出了一个阿拉伯小故事，阿拉伯人卡尔蒂首先发现并品尝了咖啡。这一段的作用是为了证明上一段的结论。所以选D。