David Bennett,an American man who received a genetically-modified(转基因的)pig heart in transplant(移植) surgery, died on Tuesday, March 8,2022. The hospital said he was doing well at first after the operation but his condition became worse several days later.

Doctors from the university of Maryland Medical center performed the operation after receiving special agreement from the U.S. government for it. The operation took seven hours.It is the first time that this has happened and proved an animal heart can survive in a human.

Before the operation.Mr Bennett was very ill and had spent the last several months in bed on a life support machine. The doctors said giving him the pig's heart was the only chance of keeping him alive.Bennett said to doctors the day before the operation.“It is either to die or to do this transplant. I want to live. I know it's a shot in the dark.but it's my last choice.”

Scientists had changed the genes(基因)of the pig so its heart would be more suitable for a transplant into a human. It was performed by firm Revivicor, which also supplied the pig used in a kidney transplant on a brain-dead patient in New York in October.

Scientists have been researching pig-organ transplants for years. They said although Mr Bennett died, this still could bring the world one step closer to solving the organ shortage(短缺)problem”.About 110,000 Americans are now waiting for an organ transplant,and more than 6,000 patients die each year before getting one. David Bennett Jr.s said,““We are grateful for every innovative moment, every crazy dream, every sleepless night that went into this historic effort. We are optimistic and believe this story is the beginning of hope and not the end.”

1.What can we learn from the first two paragraphs?

A. The government supported the operation.

B. Doctors did the operation on March8,2022.

C. Bennett didn't feel well at first after the operation.

D. Bennett's death showed animal hearts can't survive in humans.

2.What does the underlined part "a shot in the dark"probably mean?

A. A shame.

B. An accident.

C. An operation.

D. A try.

3.What did the firm Revivicor do?

A. It changed the pig's genes.

B. It created a man-made kidney.

C.It performed the heart transplant.

D. It saved many brain-dead patients.

4.Why do scientists research pig-organ transplants according to the text?

A.To solve the organ shortage problem.

B. To reduce the cost of heart transplants.

C. To develop genetically-modified technology.

D. To provide a new choice for brain-dead patients.

5. Which word can best describe David Bennett Jr.'s attitude(态度)?

A. Careless. B. Doubtful.

C. Confident. D. Uncertain.

答案解析：

1. A. The government supported the operation.

解析：根据第二段中的 "Doctors from the University of Maryland Medical Center performed the operation after receiving special agreement from the U.S. government for it." 可以得知，医生们在得到美国政府的特别许可后进行了手术，说明政府支持这次手术。

2. D. A try.

解析：根据画线部分的前后文 "It's my last choice." 可以推断，"a shot in the dark" 意味着在没有把握的情况下尝试，所以答案是 D。

3. A. It changed the pig's genes.

解析：根据第四段中的 "It was performed by firm Revivicor, which also supplied the pig used in a kidney transplant on a brain-dead patient in New York in October." 可以得知，Revivicor 公司提供了用于移植的转基因猪，所以答案是 A。

4. A. To solve the organ shortage problem.

解析：根据最后一段中的 "Scientists have been researching pig-organ transplants for years. They said although Mr Bennett died, this still could bring the world one step closer to solving the organ shortage problem." 可以得知，科学家研究猪器官移植是为了解决器官短缺的问题，所以答案是 A。

5. C. Confident.

解析：根据最后一段中 David Bennett Jr. 的话 "We are grateful for every innovative moment, every crazy dream, every sleepless night that went into this historic effort. We are optimistic and believe this story is the beginning of hope and not the end." 可以看出他对这次尝试持乐观和自信的态度，所以答案是 C。