Milk was one of the main foods of people long before history was written. It will probably keep on being one as long as there are animals that give milk.    Even the word "milk" is very old. It comes from Sanskrit ( ), one of the oldest languages known to man. A very old picture of _ has been found. It was drawn more than five thousand years ago. In the years long ago, people got their milk from their own animals. But later new inventions made the milk industry a big business. In 1851 Gail Borden found a way to take some of the water out of milk. This made it keep much 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 that it has been. But remember how long milk has been an important food and think of many ways in which it is useful. It seems safe to say that milk industry will always be important. People got their milk mainly from their own animals   _  .
a hundred years ago. fifty years ago. one hundred and forty years ago. before a number of inventions were made.