Warm water freezes more quickly than cold water. Sir Francis Bacon said that almost four hundred years ago. But few people believed him until 1970. In that year a Canadian scientist George Kill proved the English professor was right. Dr Kill filled an open oil pail(桶) with cold water. He filled another with warm water. He put both in the same low temperature. The warm water froze first. The lack of covers on the pails is the secret. Some of the warm water changed into vapor. This meant that less of the warm water was left to be frozen. And so the warm water froze faster than the cold water even though it had a greater temperature drop to make.
小题1:Hundreds of years ago, Sir Francis Bacon found _______.
A．the temperature of warm water drops faster than that of cold water
B．warm water is heavier than cold water
C．warm water has the same temperature as cold water
D．warm water is not as useful as cold water小题2:What Sir Francis Bacon said was right, but people didn't believe him until _______.
A．late in the 19th century
B．early in the 20th century
C．three years ago
D．late in the 20th century小题3:Leave a pail with warm water and another pail with cold water in the same low temperature, you’ll find that _______.
A．cold water freezes first
B．warm water turns into ice before cold water
C．warm water and cold water freeze at the same time
D．much of cold water is changed into air.小题4:Why does warm water freeze first in the same freezing weather?
A．Because some of the warm water turns to vapor, the amount(数量) becomes less than that of cold water.
B．Because warm water is lighter than cold water.
C．Because the temperature of warm water is lower than that of cold water.
D．Because cold water freezes with more difficulty than warm water.
小题1:A
小题2:D
小题3:B
小题4:A
文章向我们介绍了一种古老的理论：热水比冷水结冰更快的。并解释了原因—热水的水蒸气带走了部分热水，剩下的热水变老了，这才是热水比冷水结冰更快的原因。
小题1:A 推理题。文章第一句Warm water freezes more quickly than cold water.温水比冷水更快结冰，热水的温度比冷水的温度要高，而结冰的时候都是零度了，这说明热水的温度降的更快。故A正确。
小题2:D 细节题。根据文章第二行But few people believed him until 1970.人们直到20世纪70年代才相信这个理论。20实际70年代属于20世纪的晚期，故D正确。
小题3:B 细节题。根据文章4,5行Dr Kill filled an open oil pail(桶) with cold water. He filled another with warm water. He put both in the same low temperature. The warm water froze first.说明温水更快结冰，那么是在冷水结冰之前就结冰了，故B正确。
小题4:A 细节题。根据文章倒数3,4行Some of the warm water changed into vapor. This meant that less of the warm water was left to be frozen.说明部分热水变成了水蒸气，留下的热水变少了，这才是热水比冷水结冰更快的原因。故A正确。
点评：科技类说明文一直是高考中必考内容，本文相对比较简单，生词较少，难度较小，此类文章不要有畏难心理。对于那些生词，不要畏惧，因为对答案都没有影响。
