题目内容：

    Robert Jarvik, born on May 11, 1946 in Michigan and raised in Stamford, is a medical scientist and researcher, who played an important role in the invention of the artificial heart. He was interested in medicine from a young age. He watched his father perform operations and gained a patent (专利权) for a machine applied in the medical operation before he graduated from high school.

Jarvik attended Syracuse University and considered a career in art. When his father developed heart disease suddenly, he decided then to work on a medical career. He applied to medical schools, but was not admitted to any schools in the US. Before long, he was admitted to the medical school in Italy and stayed there for two years. He returned to get a degree in medicine from New York University in 1971.

After working for a period of time, Jarvik got a job in the organ transplant (器官移植) program at the University of Utah in 1972. He worked with the director of the program, Willem Kolff, who invented the kidney dialysis (肾透析) machine.

By the time Jarvik came to the University of Utah, the organ program had already developed the primary artificial heart. He improved it by creating a diaphragm (横膈膜), which solved many issues with the heart. Eventually, he created the first artificial heart in 1981, the Jarvik-7, to be placed in a human patient, which was considered one of the most important inventions in human history.

Barney Clark, a retired dentist suffering from serious heart disease, received the Jarvik-7 transplant on December 2, 1982. He lived for 112 days after the operation, but the transplant was considered a success. Though receiving criticism for the risk referred to transplant an artificial heart, the Jarvik-7 still became very important for patients who were waiting for a heart. In 1987, Jarvik moved to New York City and formed Jarvik Research Inc. He began developing a new heart — the Jarvik 2000. This smaller machine fits inside a patient’s heart rather than replacing the entire organ.

1.What method does the writer use to develop the passage?

A.By discussing research experiments.

B.By following the natural time order.

C.By presenting some research results.

D.By comparing opinions from different fields.

2.The underlined word “issues” in Paragraph 4 probably means “________”.

A.items B.incidents

C.problems D.debates

3.Which of the following incidents made Robert Jarvik determine his life-long career?

A.His father developed heart disease suddenly.

B.He received a patent for the medical operation.

C.He took part in the organ program at the University of Utah.

D.He was refused to be admitted to any medical school in the US.

4.What is the greatest achievement for Robert Jarvik as a medical scientist?

A.He invented the kidney dialysis machine.

B.He created the first artificial heart in 1981.

C.He created a diaphragm to fit inside a patient’s heart.

D.He did the first heart transplant operation for a heart patient.