第4部分：阅读理解（第31—45题，每题3分，共45分) 下面有3篇短文，每篇短文后有5道题，每道题后

第4部分：阅读理解(第31—45题，每题3分，共45分) 下面有3篇短文，每篇短文后有5道题，每道题后面有4个选项。请根据文章的内容，从每题所给的4个选项中选择1个最佳答案，涂在答题卡相应的位置上。

第一篇：

What Is Death？

People in the past did not question the difference between life and death. They could see that a person died when his heart stopped beating. People have learned, however, that the body does not die immediately when the heart stops beating. They discovered that we remain alive as long as our brain remains active. Today the difference between life and death is not as easy to see as in the past. Modern medical devices can keep the heart beating and the lungs breathing long after the brain stops. But is this life？

This question has caused much debate among citizens in the United States. Many of them want a law that says a person is dead when the brain dies. A person should be considered dead when brain waves stop even if machines can keep the body alive. Such a law would permit doctors to speed removal(切除) of undiseased(没病的)organs for transplant(移植) operations.

The brain is made of thousands of millions of nerve cells. These cells send and receive millions of chemical and electrical messages every day. In this way the brain controls the other body activities. Nerve-cell experts say it usually is easy to tell when the brain has died. They put small electrodes(电极) on a person’s skull (头骨) to measure the electrical signals that pass in and out of the brain. These brain waves are recorded on a television screen or on paper. The waves move up and down every time the brain receives messages from the nerve cells. The brain is dead when the waves stop moving.

Although there are people who oppose the idea of a law on brain block for variouis reasons, the idea of brain wave activity as a test of death is slowly being accepted.

第31题：People in the past held that the difference between life and death

A.was easy to tell.

B.did not exist.

C.lay in the brain.

D.was open to debate.