What Is Death? % V8 N- j% G9 a" U: q
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?
1 e$ k. y/ p; n/ ^8 T2 N 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. / g0 w. s8 F- g. R4 [
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.
2 y7 o- f, C/ } Although there are people who oppose the idea of a law on brain block for various reasons, the idea of brain wave activity as a test of death is slowly being accepted. / B I1 [8 m% R1 \( P. Q+ [
1 People in the past held that the difference between life and death
: n2 W" U. v* T. e1 A6 w A did not exist. & x1 \8 v. G* _0 \) ]
B was easy to tell.
0 k, V! h# D O; q$ A" H7 `6 l C lay in the brain.
/ ~( r( n3 F5 A; P; ~ D was open to debate.
8 Y: f2 h& j$ m 2 Which of the following is NOT a phenomenon mentioned in the passage? - J0 m& g; B% n2 D4 `: s
A The body may still be alive after the heart and the brain have stopped working K' @. g( \- O# O9 B
B The heart may keep beating after the brain has died. : c( ]. \* _+ c
C The brain may still be active after the heart has stopped beating.
0 h* n7 e* c1 n. c1 E5 @ D The lung may keep breathing after the brain has died. 5 X% P8 ]/ r, |2 S
3 When a person should be considered dead is currently a matter
* m6 D7 n9 }7 `2 [& P9 o A which few people in the US care much about.
$ D' J! C3 Y' U B which has caused heated argument in the US. ) a3 ^" s7 ^: @! ?: J
C which only doctors can settle.
. z0 Q+ G( C$ y( e/ `5 P7 J D which has already been settled.
8 i( `0 V+ a# |7 y, m8 ~) o- Z 4 The brain controls the other body activities through
& d8 J; r: l: Z7 t, h4 ~ A medical devices. " R% ?1 n/ p2 F) A3 t5 `4 Y
B small electrodes
) _; u0 ]1 {4 l! @" W) O C the nerve cells.
2 b! N( w. `/ o8 i D the brain waves. : i$ Q, _1 f9 u6 K# i: k4 {
5 More and more people are beginning to accept the idea that a person is dead
9 C3 Z8 P5 `4 _: | A when the heart stops beating. 6 ?2 A( z* [$ f1 Z. v
B when the brain becomes less active. : B7 q4 f+ q3 a
C when the brain stops working.
! C# {) M) b: e. b D when doctors stop medical treatment. 0 i+ Q9 Y% r6 v0 N' p
【参考答案】
1 Y! _; f6 f4 f* J8 p 1. B 2. A 3. B 4. C 5. C |