Questions 23 to 25 are based on the passage you have just heard.
A.They can grow in labs.
B.They can form different organs.
C.They have resistance against drugs.
D.They are newly found.
A.Have a very good rest.
B.Forget about the operation.
C.Be aware of the rejection.
D.Take drugs regularly.
A.People are still unknown about stem cells.
B.People feel it is against their religious belief.
C.The cost of developing stem cells is too high.
D.It puts babies' lives in great danger.
Some people are calling it the greatest medical breakthrough so far this century. Surgeons in Spain have successfully carried out the world's first organ transplant using new stem cell technology.
But what are stem cells? Most cells in our bodies are designed to serve specific purposes—for example, a liver cell develops to work in the liver and cannot become a heart cell. But stem cells are different. (23) They are very young, and in the laboratory scientists can grow them into different types of cell. (24) Currently, transplant patients have to take drugs for the rest of their lives to prevent their bodies rejecting the new organs. These drugs can have bad side-effects, and do not always prevent rejection. But by using Ms Castillo's own cells, doctors were able to trick her body into thinking the new part was her own organ. Five months on, Claudia Castillo is in perfect health. This ground-breaking procedure could be used in other transplant operations in the future. Scientists also believe stem cells might be used to treat Parkinson's disease, Alzheimer's disease, heart disease, stroke, and burns.
However, stem cell research is extremely controversial. The most effective stem cells do not come from adults but from embryos created in laboratories and which are just a few days old. (25) Many people have religious or ethical objections to growing embryos, even if they can be used to cure diseases.
23. What makes stem cells so special?
24. What must organ transplant patients do after the operation?
25. Why do some people disagree with the use of stem cells in disease treatment?