阅读理解。
Whatever our differences as human beings are we all think we're more like the rest of the animal world
than we realize. It is said that we share 40 percent of our genetic (遗传的) structure with the simple worm.
But that fact has helped Sir John Sulston win the 2002 Nobel Prize for Medicine. Sir John is the founder
of the Sanger Institute in Cambridge, which was set up in 1992 to get further understanding of the human
genome (染色体组).
To help them do this, they turned to the worm. The nematode (线虫类的) worm is one of the earliest
creatures on planet earth. It is less than one millimeter long, completely transparent and spends its entire life
digging holes through sand. But it still has lots to say about human life, and what can be done to make it
better.
What the worm told Sir John and his colleagues was that each of the cells in the human body is
programmed like a computer. They grow, develop and die according to a set of instructions that are coded
in our genetic make-up.
Many of the diseases that humans suffer from happen when these instructions go wrong or are not
obeyed. When the cell refuses to die but carries on growing instead, this leads to cancer. Heart attacks and
diseases like AIDS cause more cell deaths than normal, increasing the damage they do to the body. Sir John
was the first scientist to prove the existence of programmed cell death.
1. Sir John Sulston got a Nobel Prize for Medicine because he has _____ .
A. found that human beings are similar to the worm
B. got the fact we share 40 percent of our genetic structure with the simple worm
C. found the computer which controls each of the cells in the human body
D. proved that cell death is programmed
2. People might be seriously ill if the cells in their body _____.
A. grow without being instructed
B. die regularly
C. fail to follow people's instructions
D. develop in the human body
3. The underlined word " they" in Paragraph 5 refers to _____.
A. cell deaths
B. diseases
C. instructions
D. cells
4. What is the subject discussed in the text?
A. The theory of programmed cell deaths.
B. A great scientist-Sir John Sulston.
C. The programmed human life.
D. Dangerous diseases.
则
的值为（）．