题目内容：

Warm water freezes more quickly than cold water. Sir Francis Bacon said that almost four hundred years ago. But few people believed him. Later, a Canadian scientist George Kell proved the English scholar was right. Dr.Kell filled an open jar（罐子）with cold water. He filled another with warm water. He put them both in the same low temperature. And the warm water froze first.

  What was the reason? Some of the warm water changed into vapour. It went into the air. This meant that less of the warm water was left to freeze. And so the warm water froze faster than the cold water.

1. Sir Francis Bacon was__________________.

A. an American chemist    B. an English scholar

C. a Canadian scientist     D. a French physicist

2. Dr.Kell’s jars were both_____________________.

A. put in a place of the same low temperature

B. filled with warm water

C. left empty

D. put on a long table

3. The cold water froze more slowly because_____________.

A. there was less of it left        B. there was more of it left

C. something else was added to it  D. its jar was much bigger

4. Dr.Kell proved what Bacon said in _____________ way.

A. a difficult      B. a hard    C. a wrong    D. a simple