Milk was one of the main human foods long before history was written. It will probably remain one as long as there are animals that give milk. The old word "milk" came from Sanskrit, one of the oldest languages known to man. A very old picture of milking has been found. It was drawn five thousand years ago. In the years long ago, people got their milk from their own animals. But in modem times new inventions made the milk industry a big business. In 1851 Gall Borden found a way to take some of the water out from milk. This made milk keep longer. Four years later, Louis Pasteur introduced a way to kill the bacteria in milk. Next, a special milk bottle was made. This was followed by the invention of machines that could fill bottles with milk. These discoveries had a great effect on the milk industry. They meant that milk could be stored longer. Some people believe that milk drinking will become less popular than it has been. But remember how long milk has been an important food and think of the many ways in which it is useful. It seems safe to say that milk industry will always be important.
单选题
People began to milk animals ______.
【正确答案】
B
【答案解析】5000年前，就有挤牛奶的图画。从文章第一段第一句“Milk was one of the main human foods long before history was written.”可知在人类开始书写历史之前，牛奶就已经是人类的主要食物。所以，挤牛奶也是在史前就有的活动。所以正确答案选B。
单选题
Sanskrit is a language ______.
【正确答案】
C
【答案解析】由文章第二段第一句“The old word “milk” came from Sanskrit, one of the oldest languages known to man”可知，这种语言是一种极为古老的语言。所以正确答案选C。