【正确答案】
B
【答案解析】[听力原文]32-35
In the old days, fresh food had to be eaten in the city no more than one or two days after it left the farm. If kept longer, it would spoil. One of the reasons behind it is that the air contains many living things that can harm our food. Some things, such as insects, can be seen by us. Others, like bacteria, can be seen only with a microscope.
All living things need water and man discovered that if this water is removed, the activity of the bacteria which causes food to go bad is prevented. In other words, we can protect some of our food by drying it. 'Besides, living things can only grow at certain temperature's, so we can also protect our food by heating or cooling it.
A New York man had an idea. He filled a wooden rail- road car with tons of butter. The car was hooked to a train and pulled from New York to Boston. How could this be done? The butter was packed in ice, and twice during the trip more ice was added. This was the first refrigerator ear. As a matter of fact, People also used wooden boxes filled with ice to keep their food. Now we have mechanical refrigerator cars and mechanical refrigerators at home and stores and other places that need them.
32. In the old days, in order to avoid eating spoiled food, what was done?
[试题分析] 本题考查考生对细节的理解。
[试题详解] 过去人们为了避免吃变质了的食物,一般在新鲜食物运离农场的一两天之内将食物吃掉,故选B。